Post Effective Amendment to Registration Statement by Investment Company Form 485APOS

Vanguard Ultra-Short Treasury ETF Prospectus

xx, 202x

Exchange-traded fund shares that are not individually redeemable and are listed on XX.

Vanguard Ultra-Short Treasury ETF Shares (VGUS)

Subject to Completion

Preliminary Prospectus

Dated November 22, 2024

Information contained in this prospectus is subject to completion or amendment. A registration statement for Vanguard Ultra-Short Treasury ETF has been filed with the U.S. Securities and Exchange Commission but has not yet become effective.

Shares of Vanguard Ultra-Short Treasury ETF may not be sold, nor may offers to buy be accepted, prior to the time the registration statement becomes effective. This communication shall not constitute an offer to sell, nor shall there be any sale of these securities in any state in which such offer, solicitation, or sale would be unlawful prior to registration or qualification under the securities laws of any such state.

This is the Fund's initial prospectus, so it does not contain performance data.

The Securities and Exchange Commission (SEC) has not approved or disapproved these securities or passed upon the adequacy of this prospectus. Any representation to the contrary is a criminal offense.

Contents

ETF Summary

Investment Objective

The Fund seeks to track the performance of a market-weighted Treasury index with an ultra-short-term dollar-weighted average maturity.

Fees and Expenses

The following tables describe the fees and expenses you may pay if you buy, hold, and sell shares of the Fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and example below.

Shareholder Fees

(Fees paid directly from your investment)

*None through Vanguard (Broker fees vary)

Annual Fund Operating Expenses

(Expenses that you pay each year as a percentage of the value of your investment)

Example

The following example is intended to help you compare the cost of investing in the Fund's ETF Shares with the cost of investing in other funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund's shares. This example assumes that the Fund provides a return of 5% each year and that total annual fund operating expenses remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you were to sell your shares at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

This example does not include the brokerage commissions that you may pay to buy and sell shares of the Fund.

Portfolio Turnover

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, reduce the Fund's performance. The Fund has no operating history and therefore has no portfolio turnover information.

Principal Investment Strategies

The Fund employs an indexing investment approach designed to track the Bloomberg Short Treasury Index (the Index). The Index includes fixed income securities issued by the U.S. Treasury (not including inflation-protected bonds, floating rate securities and certain other security types), that have maturities up to 12 months.

The Fund invests by sampling the Index, meaning that it holds a range of securities that, in the aggregate, approximates the full Index in terms of key risk factors and other characteristics. Under normal circumstances, the Fund will generally invest all, but at least 80% of its assets in in the securities comprising the Index and in securities that the advisor determines have economic characteristics that are substantially identical to the economic characteristics of the securities that comprise the Index.

The Fund seeks to maintain a dollar-weighted average maturity consistent with that of the Index, which, under normal circumstances, is expected to be between 1 and 12 months. As of xx, 202x, the dollar-weighted average maturity of the Index was xx years.

Principal Risks

The Fund is designed for investors with a low tolerance for risk, but you could still lose money by investing in it. The Fund is subject to the following risks, which could affect the Fund's performance, and the level of risk may vary based on market conditions:

•Income risk, which is the chance that the Fund's income will decline because of falling interest rates. Income risk is generally high for short-term bond funds, so investors should expect the Fund's monthly income to fluctuate accordingly.

•Interest rate risk, which is the chance that bond prices overall will decline because of rising interest rates.

•Index-related risks. The Fund is subject to risks associated with index investing, which include passive management risk, tracking error risk, and index provider risk. Passive management risk is the chance that the Fund's use of an indexing strategy will negatively impact the Fund's performance. Because the

The Vanguard Group, Inc. (Vanguard)

Portfolio Manager

Joshua C. Barrickman, CFA, Principal of Vanguard and co-head of Vanguard's Fixed Income Indexing Americas. He has managed the Fund since its inception in xx.

Purchase and Sale of Fund Shares

ETF Shares may only be bought and sold in the secondary market through a brokerage firm. The price you pay or receive for ETF Shares will be the prevailing market price, which may be more (premium) or less (discount) than the NAV of the shares. The brokerage firm may charge you a commission to execute the transaction. Unless imposed by your brokerage firm, there is no minimum dollar amount you must invest and no minimum number of shares you must buy. ETF Shares cannot be directly purchased from or redeemed with the Fund, except by certain authorized broker-dealers. These broker-dealers may purchase and redeem ETF Shares only in large blocks (Creation Units), typically in exchange for baskets of securities.

An investor may incur costs attributable to the difference between the highest price a buyer is willing to pay to purchase ETF Shares (bid) and the lowest price a seller is willing to accept for ETF Shares (ask) when buying or selling shares in the secondary market (bid-ask spread). Recent information, including information on the Fund's NAV, market price, premiums and discounts, and bid-ask spreads, is available online at vanguard.com.

Tax Information

The Fund's distributions may be taxable as ordinary income or capital gain. You should consult your own tax advisor with respect to any particular U.S. or non- U.S. tax consequences of your investment in the Fund.

Payments to Financial Intermediaries

The Fund and its investment advisor do not pay financial intermediaries for sales of Fund shares.

Investing in Vanguard ETF® Shares

What Are Vanguard ETF Shares?

Vanguard ETF Shares are an exchange-traded class of shares issued by certain Vanguard funds. ETF Shares represent an interest in the portfolio of stocks or bonds held by the issuing fund.

How Are Vanguard ETF Shares Different From Conventional Mutual Fund Shares?

Conventional mutual fund shares can be directly purchased from and redeemed with the issuing fund for cash at the net asset value (NAV), typically calculated once a day. ETF Shares, by contrast, cannot be purchased directly from or redeemed directly with the issuing fund by an individual investor. Rather, ETF Shares can only be purchased or redeemed directly from the issuing fund by certain authorized broker-dealers. These broker-dealers may purchase and redeem ETF Shares only in large blocks (Creation Units), usually in exchange for baskets of securities and not for cash (although some funds issue and redeem Creation Units in exchange for cash or a combination of cash and securities).

An organized secondary trading market is expected to exist for ETF Shares, unlike conventional mutual fund shares, because ETF Shares are listed for trading on a national securities exchange. Individual investors can purchase and sell ETF Shares on the secondary market through a broker. Secondary-market transactions occur not at NAV, but at market prices that are subject to change throughout the day based on the supply of and demand for ETF Shares, changes in the prices of the fund's portfolio holdings, and other factors.

The market price of ETF Shares typically will differ somewhat from the NAV of those shares. The difference between market price and NAV is expected to be small most of the time, but in times of market disruption or extreme market volatility, the difference may become significant.

How Do I Buy and Sell Vanguard ETF Shares?

ETF Shares of the Fund are listed for trading on The NASDAQ Stock Market LLC. You can buy and sell ETF Shares on the secondary market in the same way you buy and sell any other exchange-traded security-through a broker. Your broker may charge a commission to execute a transaction. You will also incur the cost of the "bid-ask spread," which is the difference between the highest price a buyer is willing to pay to purchase ETF Shares (bid) and the lowest price a seller is willing to accept for ETF Shares (ask) when buying or selling shares in the secondary market. Because secondary-market transactions occur at market prices, you may pay more (premium) or less (discount) than NAV when you buy ETF Shares and receive more or less than NAV when you sell those shares. In times of severe market disruption, the bid-ask spread and premiums/discounts can increase significantly. Unless imposed by your broker, there is no minimum dollar amount you must invest and no minimum number of ETF Shares you must buy.

Your ownership of ETF Shares will be shown on the records of the broker through which you hold the shares. Vanguard will not have any record of your ownership. Your account information will be maintained by your broker, which will provide you with account statements, confirmations of your purchases and sales of ETF Shares, and tax information. Your broker also will be responsible for ensuring that you receive income and capital gains distributions, as well as shareholder reports and other communications from the fund whose ETF Shares you own. You will receive other services (e.g., dividend reinvestment and average cost information) only if your broker offers these services.

More on the Fund and ETF Shares

This prospectus describes the principal risks you would face as a Fund shareholder. It is important to keep in mind one of the main principles of investing: generally, the higher the risk of losing money, the higher the potential reward. The reverse, also, is generally true: the lower the risk, the lower the potential reward. As you consider an investment in any fund, you should take into account your personal tolerance for fluctuations in the securities markets. Throughout the prospectus, this  symbol is used to mark detailed information about some of the risks that you would confront as a Fund shareholder. To highlight terms and concepts important to fund investors, we have provided Plain Talk® explanations along the way. Reading the prospectus will help you decide whether the Fund is the right investment for you. We suggest that you keep this prospectus for future reference.

A Note to Investors

Vanguard ETF Shares can be purchased directly from the issuing Fund only by certain authorized broker-dealers in exchange for a basket of securities (or, in some cases, for cash or a combination of cash and securities). Individual investors generally will not be able to purchase ETF Shares directly from the Fund. Instead, these investors will purchase ETF Shares on the secondary market through a broker.

Plain Talk About Fund Expenses

All funds have operating expenses. These expenses, which are deducted from a fund's gross income, are expressed as a percentage of the net assets of the fund. Assuming that operating expenses remain as stated in the Fees and Expenses section, Vanguard Ultra-Short Treasury ETF Shares' expense ratio would be 0.xx%, or $xx per $1,000 of average net assets.

Plain Talk About Costs of Investing

Costs are an important consideration in choosing an ETF. That is because you, as a shareholder, pay a proportionate share of the costs of operating a fund and any transaction costs incurred when the fund buys or sells securities. These costs can erode a substantial portion of the gross income or the capital appreciation a fund achieves. Even seemingly small differences in expenses can, over time, have a dramatic effect on a fund's performance.

The following sections explain the principal investment strategies and policies that the Fund uses in pursuit of its investment objective. The Fund's board of trustees, which oversees the Fund's management, may change investment strategies or policies in the interest of shareholders without a shareholder vote, unless those strategies or policies are designated as fundamental. Note that the Fund's investment objective is not fundamental and may be changed without a shareholder vote. Under normal circumstances, the Fund will generally invest all, but at least 80% of its assets in the securities comprising the Index and in securities that Vanguard determines have economic characteristics that are substantially identical to the economic characteristics of the securities that comprise the Index. A Fund may change its 80% policy only upon 60 day's notice to shareholders.

Market Exposure

The Fund invests mainly in bonds. As a result, it is subject to certain risks.

The Fund is subject to interest rate risk, which is the chance that bond prices will decline because of rising interest rates.

Although fixed income securities (commonly referred to as bonds) are often thought to be less risky than stocks, there have been periods when bond prices have fallen significantly because of rising interest rates. For instance, prices of long-term bonds fell by almost 48% between December 1976 and September 1981.

To illustrate the relationship between bond prices and interest rates, the following table shows the effect of a 1% and a 2% change (both up and down) in interest rates on the values of three noncallable bonds (i.e., bonds that cannot be redeemed by the issuer) of different maturities, each with a face value of $1,000.

How Interest Rate Changes Affect the Value of a $1,000 Bond1

1 Assuming a 4% coupon rate.

These figures are for illustration only; you should not regard them as an indication of future performance of the bond market as a whole or the Fund in particular.

Plain Talk About Bonds and Interest Rates

As a rule, when interest rates rise, bond prices fall. The opposite is also true: bond prices go up when interest rates fall. Why do bond prices and interest rates move in opposite directions? Let's assume that you hold a bond offering a 4% yield. A year later, interest rates are on the rise and bonds of comparable quality and maturity are offered with a 5% yield. With higher-yielding bonds available, you would have trouble selling your 4% bond for the price you paid-you would probably have to lower your asking price. On the other hand, if interest rates were falling and 3% bonds were being offered, you should be able to sell your 4% bond for more than you paid.

Changes in interest rates can affect bond income as well as bond prices.

The Fund is subject to income risk, which is the chance that the Fund's income will decline because of falling interest rates. A fund's income declines when interest rates fall because the fund then must invest new cash flow and cash from maturing bonds in lower-yielding bonds. Income risk is generally high for short-term bond funds, so investors should expect the Fund's monthly income to fluctuate accordingly.

Plain Talk About Bond Maturities

A bond is issued with a specific maturity date-the date when the issuer must pay back the bond's principal (face value). Bond maturities range from less than 1 year to more than 30 years. Typically, the longer a bond's maturity, the more price risk you, as a bond investor, will face as interest rates rise-but also the higher the potential yield you could receive. Longer-term bonds are generally more suitable for investors willing to take a greater risk of price fluctuations to get higher and more stable interest income. Shorter-term bond investors should be willing to accept lower yields and greater income variability in return for less fluctuation in the value of their investment. The stated maturity of a bond may differ from the effective maturity of a bond, which takes into consideration that an action such as a call or refunding may cause bonds to be repaid before their stated maturity dates.

Although falling interest rates tend to strengthen bond prices, they can cause other problems for bond fund investors-bond calls and prepayments.

Plain Talk About Types of Bonds

Bonds are issued (sold) by many sources: Corporations issue corporate bonds; the federal government issues U.S. Treasury bonds; agencies of the federal government issue agency bonds; financial institutions issue asset- backed bonds; and mortgage holders issue "mortgage-backed" pass-through certificates. Each issuer is responsible for paying back the bond's initial value as well as for making periodic interest payments. Many bonds issued by government agencies and entities are neither guaranteed nor insured by the U.S. government.

Market disruptions can adversely affect local and global markets as well as normal market conditions and operations. Any such disruptions could have an adverse impact on the value of the Fund's investments and Fund performance.

Security Selection

Index sampling strategy. Because it would be very expensive and inefficient to buy and sell all bonds held in its target index-which is an indexing strategy called "full replication"-the Fund uses index "sampling" techniques to select securities. Using sophisticated quantitative and qualitative methods, the Fund's advisor generally selects a representative sample of securities that approximates the full target index in terms of key risk factors and other characteristics. These factors include duration, cash flow, quality, and callability of the underlying bonds.

The Fund seeks to track the performance of the Bloomberg Short Treasury Index, which includes U.S. Treasury Bills, Notes, and Bonds between 1-12 months of maturity. The Index measures the performance of the investment- grade, fixed-rate U.S. municipal bond market with maturities between one and twelve months as determined by the Index provider, Bloomberg. The components of the Index are reconstituted and rebalanced on a monthly basis. The Index rebalances as a market-weighted index, and bonds may enter or fall out of the Index on a monthly basis. New securities are added to and removed from the Index in connection with the month-end index rebalancing process.

The types of financial instruments that may be purchased by the Fund are identified and explained as follows:

•U.S. government and agency bonds represent loans by investors to the U.S. Treasury or a wide variety of government agencies and instrumentalities. Securities issued by most U.S. government entities are neither guaranteed by the U.S. Treasury nor backed by the full faith and credit of the U.S. government. These entities include, among others, the Federal Home Loan Banks (FHLBs), the Federal National Mortgage Association (FNMA), and the Federal Home Loan Mortgage Corporation (FHLMC). Securities issued by the U.S. Treasury and a small number of U.S. government agencies, such as the Government National Mortgage Association (GNMA), are backed by the full faith and credit of the U.S. government. The market values of U.S. government and agency securities and U.S. Treasury securities are subject to fluctuation. The Fund may concentrate (invest over 25%) its investments in government securities.

Index Investing and Risks

The Fund is an index fund. Index funds attempt to track - not outperform - the performance of a specified market index (target index). An index is a group of securities whose overall performance is used as a standard to measure the investment performance of a particular market. Some indexes represent entire markets, such as the U.S. stock market, while others cover a segment of a market, such as short-term bonds. As an index fund, the Fund seeks to track the performance of its target index regardless of how the target index is performing. The advisor's use of an indexing, or passive, approach to select and maintain investments for the Fund means that the advisor will select securities based on their inclusion in the target index and will not use strategies to reduce negative

impacts to the Fund during periods of market volatility. As a result, the Fund's performance may be lower than it would be if the Fund were actively managed.

One cannot invest directly in an index. Instead, an index fund's advisor will typically seek to hold all, or substantially all, of the securities that make up the fund's target index (often referred to as "replicating" an index or a "full replication" approach) or a representative sample of the securities that make up a fund's target index (often referred to as "sampling" an index).

The Fund is subject to index sampling risk, which is the chance that the securities selected for the Fund, in the aggregate, will not provide investment performance matching that of the Fund's target index. Index sampling risk for the Fund is expected to be low to moderate.

As an index fund, the Fund is subject to tracking error. It is important to understand that an index fund will never perform exactly the same as its target index because, among other things, an index fund will have operating expenses and transaction costs and its target index will not. Beyond these inherent differences between the operation of an index fund and the operation of its target index, there are a variety of other factors that can cause or result in tracking error. These may include, but are not limited to:

•Price differences between the securities held by an index fund and those included in its target index

•Cash flows into or out of an index fund

•The size of an index fund

•Compliance with new or existing regulatory requirements

•Portfolio transactions carried out by an index fund's advisor to minimize the distribution of capital gains

•Changes to the underlying securities that make up an index fund's target index

•Errors made by the index provider

Tracking error risk may be heightened during times of increased market volatility or under other unusual market conditions. An index fund that samples its target index may be more likely to experience tracking error than an index fund that replicates its target index.

The Fund is subject to risks associated with the provider of its target index. The index provider determines which securities to include in the target index and how the securities are weighted. The index provider does not provide any warranty or accept any liability with respect to the quality, accuracy, or completeness of the target index or any data used to compile the target index. Under normal circumstances, the index provider will rebalance (update) the target index on a regular schedule. The index provider may rebalance the target index outside of the regular schedule or delay or cancel a scheduled rebalance, which could result in added costs for the Fund or cause the Fund to experience tracking error. The index provider may make errors, and it is possible that such errors

The Fund may invest up to 15% of its net assets in illiquid securities. Illiquid securities are investments that a fund reasonably expects cannot be sold or disposed of in current market conditions in seven calendar days or less without the sale or disposition significantly changing the market value of the investment. Restricted securities are a special type of illiquid security; these securities have not been publicly issued and legally can be resold only to qualified buyers.

The Fund may invest a small portion of its assets in fixed income futures, which are a type of derivative, and/or shares of ETFs. These fixed income futures and ETFs typically provide returns similar to those of bonds and may purchase futures or ETFs when doing so will reduce the Fund's transaction costs, facilitate cash management, mitigate risk, or have the potential to add value because the instruments are favorably priced. Vanguard receives no additional revenue from Fund assets invested in ETF Shares of other Vanguard funds. Fund assets invested in ETF Shares of other Vanguard Funds are excluded when allocating to the Fund its share of the costs of Vanguard operations.

The Fund may invest in derivatives. In general, investments in derivatives may involve risks different from, and possibly greater than, those of investments directly in the underlying securities or assets.

Generally speaking, a derivative is a financial contract whose value is based on the value of a financial asset (such as a stock, a bond, or a currency), a physical asset (such as gold, oil, or wheat), a market index, or a reference rate. The Fund may invest in derivatives only if the expected risks and rewards of the derivatives are consistent with the investment objective, policies, strategies, and risks of the Fund as disclosed in this prospectus. In particular, derivatives will be used only when they may help the advisor to accomplish one or more of the following:

•Invest in eligible asset classes with greater efficiency and lower cost than is possible through direct investment.

•Add value when these instruments are attractively priced.

•Adjust sensitivity to changes in interest rates.

•Adjust the overall credit risk of the portfolio or actively overweight or underweight credit risk to specific bond issuers.

•Hedge foreign currency exposure.

•Hedge foreign interest rate exposure.

The Fund's derivative investments may include fixed income futures contracts; fixed income options, including options on swaps; currency swaps; foreign currency exchange forwards; interest rate swaps; total return swaps; credit default swaps; or other derivatives. Losses (or gains) involving futures contracts can sometimes be substantial-in part because a relatively small price movement in a futures contract may result in an immediate and substantial loss (or gain) for a fund. Similar risks exist for other types of derivatives.

Plain Talk About Derivatives

Derivatives can take many forms. Some forms of derivatives-such as exchange-traded futures and options on securities, commodities, or indexes- have been trading on regulated exchanges for decades. These types of derivatives are standardized contracts that can easily be bought and sold and whose market values are determined and published daily. On the other hand, non-exchange-traded derivatives-such as certain swap agreements and foreign currency exchange forward contracts-tend to be more specialized or complex and may be more difficult to accurately value.

Cash Management

The Fund's daily cash balance may be invested in Vanguard Market Liquidity Fund, a government money market fund, and/or Vanguard Municipal Low Duration Fund, a short-term municipal bond fund (each, a CMT Fund), which are low-cost money market funds. When investing in a CMT Fund, the Fund bears its proportionate share of the expenses of the CMT Fund in which it invests. Vanguard receives no additional revenue from Fund assets invested in a CMT Fund.

Redemption Requests

Methods used to meet redemption requests. Redemptions of ETF Shares are typically met through a combination of cash and securities held by the Fund; see "How Are Vanguard ETF Shares Different From Conventional Mutual Fund Shares?" If cash is used to meet redemptions, the Fund typically obtains such cash through positive cash flows or the sale of Fund holdings consistent with the Fund's investment objective and strategy. Please consult the Fund's Statement of Additional Information for further information on redemptions of ETF Shares.

Under certain circumstances, including under stressed market conditions, the Fund may borrow money (subject to certain regulatory conditions and if available under board-approved procedures) through an interfund lending facility; through a bank line-of-credit, including a joint committed credit facility; or through an uncommitted line-of-credit from Vanguard in order to meet redemption requests.

ETF Shares are not individually redeemable. They can be redeemed with the issuing Fund at NAV only by certain authorized broker-dealers and only in large blocks known as Creation Units. Consequently, if you want to liquidate some or all of your ETF Shares, you must sell them on the secondary market at prevailing market prices.

The market price of ETF Shares may differ from NAV. Although it is expected that the market price of an ETF Share typically will approximate its NAV, there may be times when the market price and the NAV differ significantly. Thus, you may pay more (premium) or less (discount) than NAV when you buy ETF Shares on the secondary market, and you may receive more or less than NAV when you sell those shares. These discounts and premiums are likely to be greatest during times of market disruption or extreme market volatility.

Vanguard's website at vanguard.com shows the previous day's closing NAV and closing market price for the Fund. The website also discloses, in the Premium/Discount Analysis section of the Fund's Price & Performance page, how frequently the Fund traded at a premium or discount to NAV (based on closing NAVs and market prices) and the magnitudes of such premiums and discounts.

An active trading market may not exist. Although Vanguard ETF Shares are listed on a national securities exchange, it is possible that an active trading market may not be maintained. Although this could happen at any time, it is more likely to occur during times of severe market disruption. If you attempt to sell your ETF Shares when an active trading market is not functioning, you may have to sell at a significant discount to NAV. In extreme cases, you may not be able to sell your shares at all.

Trading may be halted. Trading of Vanguard ETF Shares on an exchange may be halted by the activation of individual or marketwide trading halts (which halt trading for a specific period of time when the price of a particular security or overall market prices decline by a specified percentage). Trading of ETF Shares may also be halted if (1) the shares are delisted from the listing exchange without first being listed on another exchange or (2) exchange officials determine that such action is appropriate in the interest of a fair and orderly market or for the protection of investors.

A precautionary note to investment companies: The Fund's ETF Shares are issued by registered investment companies, and therefore the acquisition of such shares by other investment companies and private funds is subject to the restrictions of Section 12(d)(1) of the Investment Company Act of 1940 (the 1940 Act). SEC Rule 12d1-4 under the 1940 Act permits registered investment companies to invest in other registered investment companies beyond the limits in Section 12(d)(1), subject to certain conditions, including that funds with different investment advisors must enter into a fund of funds

investment agreement.

Shareholder Rights

The Fund's Agreement and Declaration of Trust, as amended, requires a shareholder bringing a derivative action on behalf of Vanguard Institutional Index Funds (the Trust) that is subject to a pre-suit demand to collectively hold at least 10% of the outstanding shares of the Trust or at least 10% of the outstanding shares of the series or class to which the demand relates and to undertake to reimburse the Trust for the expense of any counsel or advisors used when considering the merits of the demand in the event that the board of trustees determines not to bring such action. In each case, these requirements do not apply to claims arising under the federal securities laws to the extent that any such federal securities laws, rules, or regulations do not permit such application. The Fund's Bylaws also provide that shareholders waive the right to trial by jury to the fullest extent permitted by law.

Frequent Trading and Market-Timing

Unlike frequent trading of a Vanguard fund's conventional (i.e., not exchange- traded) classes of shares, frequent trading of ETF Shares does not disrupt portfolio management or otherwise harm fund shareholders. The vast majority of trading in ETF Shares occurs on the secondary market. Because these trades do not involve the issuing fund, they do not harm the fund or its shareholders. Certain broker-dealers are authorized to purchase and redeem ETF Shares directly with the issuing fund. Because these trades typically are effected in kind (i.e., for securities and not for cash), or are assessed a transaction fee when effected in cash, they do not cause any of the harmful effects to the issuing fund (as previously noted) that may result from frequent trading. For these reasons, the board of trustees of each fund that issues ETF Shares has determined that it is not necessary to adopt policies and procedures to detect and deter frequent trading and market-timing of ETF Shares.

Portfolio Holdings

Please consult the Fund's Statement of Additional Information or our website for a description of the policies and procedures that govern disclosure of the Fund's portfolio holdings.

Turnover Rate

Although the Fund generally seeks to invest for the long term, it may sell securities regardless of how long they have been held. In general, the greater the turnover rate, the greater the impact transaction costs will have on a fund's return. Also, funds with high turnover rates may be more likely to generate capital gains, including short-term capital gains, that must be distributed to shareholders and will be taxable to shareholders investing through a taxable account. The Fund has no operating history and therefore has no portfolio turnover information.

The Fund and Vanguard

The Fund is a member of The Vanguard Group, Inc. (Vanguard), a family of over 200 funds. All of the funds that are members of Vanguard (other than funds of funds) share in the expenses associated with administrative services and business operations, such as personnel, office space, and equipment.

Vanguard Marketing Corporation provides marketing services to the funds. Although fund shareholders do not pay sales commissions or 12b-1 distribution fees, each fund (other than a fund of funds) or each share class of a fund (in the case of a fund with multiple share classes) pays its allocated share of the Vanguard funds' marketing costs.

Plain Talk About Vanguard's Unique Corporate Structure

Vanguard is owned jointly by the funds it oversees and thus indirectly by the shareholders in those funds. Most other mutual funds are operated by management companies that are owned by third parties-either public or private stockholders-and not by the funds they serve.

Investment Advisor

The Vanguard Group, Inc., P.O. Box 2600, Valley Forge, PA 19482, which began operations in 1975, serves as advisor to the Fund through its Fixed Income Group. As of xx, Vanguard served as advisor for approximately $xx trillion in assets. Vanguard provides investment advisory services to the Fund pursuant to the Funds' Service Agreement and subject to the supervision and oversight of the trustees and officers of the Fund.

Although the Fund is managed solely by Vanguard, the Fund reserves the right to utilize a multi-manager approach in the future. Under the terms of an SEC exemption, the Fund's board of trustees may, without prior approval from shareholders, change the terms of an advisory agreement with a third-party investment advisor or hire a new third-party investment advisor-either as a replacement for an existing advisor or as an additional advisor. Any significant change in the Fund's advisory arrangements will be communicated to shareholders in writing. As the Fund's sponsor and overall manager, Vanguard may provide investment advisory services to the Fund at any time. Vanguard

may also recommend to the board of trustees that an advisor be hired, terminated, or replaced or that the terms of an existing advisory agreement be revised. The Fund has filed an application seeking a similar SEC exemption with respect to investment advisors that are wholly owned subsidiaries of Vanguard. If the exemption is granted, the Fund may rely on the new SEC relief.

For a discussion of why the board of trustees approved the Fund's investment advisory arrangement, see the Fund's first Financial Statements and Other Information to shareholders following the Fund's commencement of operations.

The manager primarily responsible for the day-to-day management of the Fund is:

Joshua C. Barrickman, CFA, Principal of Vanguard and co-head of Vanguard's Fixed Income Indexing Americas. He has been with Vanguard since 1998, has worked in investment management since 1999 has managed investment portfolios since 2005, and has managed the Fund since its inception in xx. Education: B.S., Ohio Northern University; M.B.A., Lehigh University.

The Fund's Statement of Additional Information provides information about the portfolio manager's compensation, other accounts under management, and ownership of shares of the Fund.

Dividends, Capital Gains, and Taxes

Fund Distributions

The Fund distributes to shareholders virtually all of its net income (interest less expenses) as well as any net short-term or long-term capital gains realized from the sale of its holdings. From time to time, the Fund may also make distributions that are treated as a return of capital. Income dividends generally are declared monthly and distributed monthly; capital gains distributions, if any, generally occur annually in December. In addition, the Fund may occasionally make a supplemental distribution at some other time during the year.

Plain Talk About Distributions

As a shareholder, you are entitled to your portion of a fund's income from interest as well as capital gains from the fund's sale of investments. Income consists of interest the fund earns from its money market and bond investments. Capital gains are realized whenever the fund sells securities for higher prices than it paid for them. These capital gains are either short-term or long-term, depending on whether the fund held the securities for one year or less or for more than one year.

Reinvestment of Distributions

In order to reinvest dividend and capital gains distributions, investors in the Fund must hold their shares at a broker that offers a reinvestment service. This can be the broker's own service or a service made available by a third party, such as the broker's outside clearing firm or the Depository Trust Company (DTC). If a reinvestment service is available, distributions of income and capital gains can automatically be reinvested in additional whole and fractional ETF Shares of the Fund. If a reinvestment service is not available, investors will receive their distributions in cash. To determine whether a reinvestment service is available and whether there is a commission or other charge for using this service, consult your broker.

As with all exchange-traded funds, reinvestment of dividend and capital gains distributions in additional ETF Shares will occur two business days or more after the ex-dividend date (the date when a distribution of dividends or capital gains is deducted from the price of the Fund's shares). The exact number of days depends on your broker. During that time, the amount of your distribution will not be invested in the Fund and therefore will not share in the Fund's income, gains, and losses.

Basic Tax Points

Investors in taxable accounts should be aware of the following basic federal income tax points:

•Distributions are taxable to you whether or not you reinvest these amounts in additional ETF Shares.

•Distributions declared and recorded in December-if paid to you by the end of January-are taxable as if received in December.

•Any income dividend distribution or short-term capital gains distribution that you receive is taxable to you as ordinary income.

•Any distribution of net long-term capital gains is taxable to you as long-term capital gains, no matter how long you have owned ETF Shares.

•Capital gains distributions can occur when the Fund sells assets at a gain. Capital gains distributions vary from year to year as a result of the Fund's investment activities and cash flows, including those due to redemption activity by Fund shareholders.

•Capital gains distributions may occur if Vanguard makes changes that would impact the Fund directly or indirectly, including if Vanguard makes changes to the Fund's portfolio or to any other Vanguard fund or product that would involve the redemption of shares of the Fund and the related sale of the Fund's investments.

•Your cost basis in the Fund will be decreased by the amount of any return of capital that you receive. This, in turn, will affect the amount of any capital gain or loss that you realize when selling your ETF Shares.

•Return of capital distributions generally are not taxable to you until your cost basis has been reduced to zero. If your cost basis is at zero, return of capital distributions will be treated as capital gains.

•A sale of ETF Shares is a taxable event. This means that you may have a capital gain to report as income, or a capital loss to report as a deduction, when you complete your tax return.

Individuals, trusts, and estates whose income exceeds certain threshold amounts are subject to a 3.8% Medicare contribution tax on "net investment income." Net investment income takes into account distributions paid by the Fund and capital gains from any sale of ETF Shares.

Income dividends and capital gains distributions that you receive, as well as your gains or losses from any sale of ETF Shares, may be subject to state and local income taxes. Depending on your state's rules, however, any dividends attributable to interest earned on direct obligations of the U.S. government may be exempt from state and local taxes. Vanguard will notify you each year how much, if any, of your dividends may qualify for this exemption.

This prospectus provides general tax information only. If you are investing through

atax-advantaged account, such as an IRA or an employer-sponsored retirement or savings plan, special tax rules apply. Please consult your tax advisor for detailed information about any tax consequences for you.

Share Price and Market Price

Share price, also known as net asset value (NAV), is typically calculated as of the close of regular trading on the New York Stock Exchange (NYSE), generally 4 p.m., Eastern time, on each day that the NYSE is open for business (a business day). In the rare event the NYSE experiences unanticipated disruptions and is unavailable at the close of the trading day, NAVs will be calculated as of the close of regular trading on the Nasdaq (or another alternate exchange if the Nasdaq is unavailable, as determined at Vanguard's discretion), generally 4 p.m., Eastern time. The NAV per share is computed by dividing the total assets, minus liabilities, of the Fund by the number of Fund shares outstanding. On U.S. holidays or other days when the NYSE is closed, the NAV is not calculated, and the Fund does not sell or redeem shares. However, on those days the value of the Fund's assets may be affected to the extent that the Fund holds securities that change in value on those days (such as foreign securities that trade on foreign markets that are open).

Remember: If you buy or sell ETF Shares on the secondary market, you will pay or receive the market price, which may be higher or lower than NAV. Your transaction will be priced at NAV only if you purchase or redeem your ETF Shares in Creation Unit blocks (an option available only to certain authorized broker- dealers).

Debt securities held by a Vanguard fund are valued based on information furnished by an independent pricing service or market quotations, and are priced at fair value (the amount that the owner might reasonably expect to receive upon the current sale of the security).

The values of any foreign securities held by a fund are converted into U.S. dollars using an exchange rate obtained from an independent third party as of the close of regular trading on the NYSE. The values of any mutual fund shares, including institutional money market fund shares, held by a fund are based on the NAVs of the shares. The values of any ETF shares or closed-end fund shares held by a fund are based on the market value of the shares.

A fund also may use fair-value pricing on bond market holidays when the fund is open for business (such as Columbus Day and Veterans Day). Fair-value prices are determined by Vanguard according to procedures adopted by the board of trustees. When fair-value pricing is employed, the prices of securities used by a fund to calculate the NAV may differ from quoted or published prices for the same securities.

The Fund has authorized certain financial intermediaries and their designees, and may from time to time, authorize certain funds of funds for which Vanguard serves as the investment advisor (Vanguard Funds of Funds), to accept orders to buy or sell fund shares on its behalf. The Fund will be deemed to receive an order when accepted by the financial intermediary, its designee, or one of the Vanguard Funds of Funds, and the order will receive the NAV next computed by the Fund after such acceptance.

Vanguard's website will show the previous day's closing NAV and closing market price for the Fund's ETF Shares.

Additional Information

The Fund's Bylaws designate Delaware courts as the sole and exclusive forum for certain claims against or related to the Trust, a trustee, an officer, or other employee of the Trust, provided that, unless the Trust otherwise consents in writing, that the U.S. Federal District Courts be the sole and exclusive forum for the resolution of complaints under the Securities Act of 1933 or the 1940 Act. These provisions may limit a shareholder's ability to bring a claim in a different forum and may result in increased shareholder costs in pursuing such a claim.

Certain affiliates of the Fund and the advisor may purchase and resell ETF Shares pursuant to the prospectus.

CGS identifiers have been provided by CUSIP Global Services, managed on behalf of the American Bankers Association by Standard & Poor's Financial Services, LLC, and are not for use or dissemination in a manner that would serve as a substitute for any CUSIP service. The CUSIP Database, © 2024 American Bankers Association. "CUSIP" is a registered trademark of the American Bankers Association.

CFA® is a registered trademark owned by CFA Institute.

Glossary of Investment Terms

Authorized Participant. Institutional investors that are permitted to purchase Creation Units directly from, and redeem Creation Units directly with, the issuing fund. To be an Authorized Participant, an entity must be a participant in the Depository Trust Company and must enter into an agreement with the fund's Distributor.

Average Maturity. The average length of time until bonds held by a fund reach maturity and are repaid. In general, the longer the average maturity, the more a fund's share price fluctuates in response to changes in market interest rates. In calculating average maturity, a fund uses a bond's maturity or, if applicable, an earlier date on which the advisor believes it is likely that a maturity-shortening device (such as a call, put, refunding, prepayment, or redemption provision or an adjustable coupon rate) will cause the bond to be repaid.

Bid-Ask Spread. The difference between the highest price a buyer is willing to pay to purchase ETF Shares (bid) and the lowest price a seller is willing to accept for ETF Shares (ask) when buying or selling shares in the

secondary market.

Bloomberg Short Treasury Index. This Index includes US Treasury Bills, Notes, and Bonds between 1-12 months of maturity.

Bond. A debt security issued by a corporation, a government, or a government agency in exchange for the money the bondholder lends it. In most instances, the issuer agrees to pay back the loan by a specific date and generally to make regular interest payments until that date.

Capital Gains Distributions. Payments to fund shareholders of gains realized on securities that a fund has sold at a profit, minus any realized losses.

Cash Equivalent Investments. Cash deposits, short-term bank deposits, and money market instruments that include U.S. Treasury bills and notes, bank certificates of deposit (CDs), repurchase agreements, commercial paper, and banker's acceptances.

Corporate Bond. An IOU issued by a business that wants to borrow money. As with other types of bonds, the issuer promises to repay the borrowed money by a specific date and generally to make interest payments in the meantime.

Coupon Rate. The interest rate paid by the issuer of a debt security until its maturity. It is expressed as an annual percentage of the face value of the security.

Creation Unit. A large block of a specified number of ETF Shares. Certain broker- dealers known as "Authorized Participants" may purchase and redeem ETF Shares from the issuing fund in Creation Unit size blocks.

Dividend Distributions. Payments to fund shareholders of income from interest or dividends generated by a fund's investments.

Ex-Dividend Date. The date when a distribution of dividends and/or capital gains is deducted from the share price of a mutual fund, ETF, or stock. On the ex- dividend date, the share price drops by the amount of the distribution per share (plus or minus any market activity).

Expense Ratio. A fund's total annual operating expenses expressed as a percentage of the fund's average net assets. The expense ratio includes management and administrative expenses, but it does not include the transaction costs of buying and selling portfolio securities.

Face Value. The amount to be paid at a bond's maturity; also known as the par value or principal.

Fixed Income Security. An investment, such as a bond, representing a debt that must be repaid by a specified date, and on which the borrower may pay a fixed, variable, or floating rate of interest.

Inception Date. The date on which the assets of a fund are first invested in accordance with the fund's investment objective. For funds with a subscription period, the inception date is the day after that period ends. Investment performance is generally measured from the inception date.

Investment-Grade Bond. A debt security whose credit quality is considered by independent bond rating agencies, or through independent analysis conducted by a fund's advisor, to be sufficient to ensure timely payment of principal and

interest under current economic circumstances. Debt securities rated in one of the four highest rating categories are considered investment-grade. Other debt securities may be considered by an advisor to be investment-grade.

Joint Committed Credit Facility. The Fund may participate, along with other funds managed by Vanguard, in a committed credit facility provided by a syndicate of lenders pursuant to a credit agreement that may be renewed annually; each Vanguard fund is individually liable for its borrowings, if any, under the credit facility. The amount and terms of the committed credit facility are subject to approval by the Fund's board of trustees and renegotiation with the lender syndicate on an annual basis.

Mutual Fund. An investment company that pools the money of many people and invests it in a variety of securities in an effort to achieve a specific objective over time.

New York Stock Exchange (NYSE). A stock exchange based in New York City that is open for regular trading on business days, Monday through Friday, from 9:30 a.m. to 4 p.m., Eastern time.

Return of Capital. A return of capital occurs when a fund's distributions exceed its earnings in a fiscal year. A return of capital is a return of all or part of your original investment or amounts paid in excess of your original investment in a fund. In general, a return of capital reduces your cost basis in a fund's shares and is not taxable to you until your cost basis has been reduced to zero.

Principal. The face value of a debt instrument or the amount of money put into an investment.

Securities. Stocks, bonds, money market instruments, and other investments.

Total Return. A percentage change, over a specified time period, in a fund's net asset value, assuming the reinvestment of all distributions of dividends and capital gains.

Volatility. The fluctuations in value of a mutual fund or other security. The greater a fund's volatility, the wider the fluctuations in its returns.

Yield. Income (interest or dividends) earned by an investment, expressed as a percentage of the investment's price.

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Contents

ETF Summary

Investment Objective

The Fund seeks to track the performance of a market-weighted Treasury index with an ultra-short-term dollar-weighted average maturity.

Fees and Expenses

The following tables describe the fees and expenses you may pay if you buy, hold, and sell shares of the Fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and example below.

Shareholder Fees

(Fees paid directly from your investment)

* None through Vanguard (Broker fees vary)

Annual Fund Operating Expenses

(Expenses that you pay each year as a percentage of the value of your investment)

1 The expense information shown in the table reflects estimated amounts for the current fiscal year.

Example

The following example is intended to help you compare the cost of investing in the Fund with the cost of investing in other funds. It illustrates the hypothetical expenses that you would incur over various periods if you were to invest $10,000 in the Fund's shares. This example assumes that the Fund provides a return of 5% each year and that total annual fund operating expenses remain as stated in the preceding table. You would incur these hypothetical expenses whether or not you were to sell your shares at the end of the given period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

$xx$xx

This example does not include the brokerage commissions that you may pay to buy and sell shares of the Fund.

Portfolio Turnover

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in more taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the previous expense example, reduce the Fund's performance. The Fund has no operating history and therefore has no portfolio turnover information.

Principal Investment Strategies

The Fund employs an indexing investment approach designed to track the Bloomberg 0-3M Treasury Bill Index (the Index). The Index includes U.S. Treasury Bills (not including inflation-protected bonds, floating rate securities, and certain other security types) that have maturities of three months or less.

The Fund invests by sampling the Index, meaning that it holds a range of securities that, in the aggregate, approximates the full Index in terms of key risk factors and other characteristics. Under normal circumstances, the Fund will generally invest all, but at least 80%, of its assets in the securities comprising the Index and in securities that the advisor determines have economic characteristics that are substantially identical to the economic characteristics of the securities that comprise the Index.

In seeking to track the Index, the Fund may also invest in debt securities that are not included in the Index, cash and cash equivalents, or money market instruments, such as repurchase agreements and money market funds (including money market funds advised by the advisor). The Fund seeks to maintain a dollar-weighted average maturity consistent with that of the Index, which, under normal circumstances, is expected to be under 3 months. As of xx, 202x, the dollar-weighted average maturity of the Index was xx years.

Principal Risks

The Fund is designed for investors with a low tolerance for risk, but you could still lose money by investing in it. The Fund is subject to the following risks, which could affect the Fund's performance, and the level of risk may vary based on market conditions:

•Income risk, which is the chance that the Fund's income will decline because of falling interest rates. Income risk is generally high for short-term bond funds, so investors should expect the Fund's monthly income to fluctuate accordingly.

•Interest rate risk, which is the chance that bond prices overall will decline because of rising interest rates.

•Index-related risks. The Fund is subject to risks associated with index investing, which include passive management risk, tracking error risk, and index provider risk. Passive management risk is the chance that the Fund's use of an indexing strategy will negatively impact the Fund's performance. Because the Fund seeks to track the performance of its target index regardless of how that index is performing, the Fund's performance may be lower than it would be if the Fund were actively managed. Tracking error risk is the chance that the Fund's performance will deviate from the performance of its target index. Tracking error risk may be heightened during times of increased market volatility or under other unusual market conditions. Index provider risk is the chance that the Fund will be negatively impacted by changes or errors made by the index provider. Any gains, losses, or costs associated with or resulting from an error made by the index provider will generally be borne by the Fund and, as a result, the Fund's shareholders.

•Index sampling risk, which is the chance that the securities selected for the Fund, in the aggregate, will not provide investment performance matching that of the Fund's target index. Index sampling risk for the Fund is expected to be low.

•Derivatives risk. The Fund may invest in derivatives. In general, investments in derivatives may involve risks different from, and possibly greater than, those of investments directly in the underlying securities or assets.

Because the Fund is an exchange-traded fund (ETF) and the Fund's shares are traded on an exchange, the Fund is subject to additional risks:

•The Fund's ETF Shares are listed for trading on XX and are bought and sold on the secondary market at market prices. Although it is expected that the market price of an ETF Share typically will approximate its net asset value (NAV), there may be times when the market price and the NAV differ significantly. Thus, you may pay more or less than NAV when you buy ETF Shares on the secondary market, and you may receive more or less than NAV when you sell those shares.

•Although the Fund's ETF Shares are listed for trading on XX, it is possible that an active trading market may not be maintained, which could increase the Fund's risks as disclosed in this prospectus.

•Trading of the Fund's ETF Shares may be halted by the activation of individual or market wide trading halts (which halt trading for a specific period of time when the price of a particular security or overall market prices decline by a specified percentage). Trading of the Fund's ETF Shares may also be halted if (1) the shares are delisted from XX without first being listed on another exchange or (2) XX officials determine that such action is appropriate in the interest of a fair and orderly market or for the protection of investors.

An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Annual Total Returns

This is the Fund's initial prospectus, so it does not contain performance data.

Investment Advisor

The Vanguard Group, Inc. (Vanguard)

Portfolio Manager

Joshua C. Barrickman, CFA, Principal of Vanguard and co-head of Vanguard's Fixed Income Indexing Americas. He has managed the Fund since its inception in xx.

Purchase and Sale of Fund Shares

ETF Shares may only be bought and sold in the secondary market through a brokerage firm. The price you pay or receive for ETF Shares will be the prevailing market price, which may be more (premium) or less (discount) than the NAV of the shares. The brokerage firm may charge you a commission to execute the transaction. Unless imposed by your brokerage firm, there is no minimum dollar amount you must invest and no minimum number of shares you must buy. ETF Shares cannot be directly purchased from or redeemed with the Fund, except by certain authorized broker-dealers. These broker-dealers may purchase and redeem ETF Shares only in large blocks (Creation Units), typically in exchange for baskets of securities.

An investor may incur costs attributable to the difference between the highest price a buyer is willing to pay to purchase ETF Shares (bid) and the lowest price a seller is willing to accept for ETF Shares (ask) when buying or selling shares in the secondary market (bid-ask spread). Recent information, including information on the Fund's NAV, market price, premiums and discounts, and bid-ask spreads, is available online at vanguard.com.

Tax Information

The Fund's distributions may be taxable as ordinary income or capital gain. If you are investing through a tax-advantaged account, such as an IRA or an employer- sponsored retirement or savings plan, special tax rules apply. You should consult your own tax advisor with respect to any particular U.S. or non-U.S. tax consequences of your investment in the Fund.

Payments to Financial Intermediaries

The Fund and its investment advisor do not pay financial intermediaries for sales of Fund shares.

Investing in Vanguard ETF® Shares

What Are Vanguard ETF Shares?

Vanguard ETF Shares are an exchange-traded class of shares issued by certain Vanguard funds. ETF Shares represent an interest in the portfolio of stocks or bonds held by the issuing fund.

How Are Vanguard ETF Shares Different From Conventional Mutual Fund Shares?

Conventional mutual fund shares can be directly purchased from and redeemed with the issuing fund for cash at the net asset value (NAV), typically calculated once a day. ETF Shares, by contrast, cannot be purchased directly from or redeemed directly with the issuing fund by an individual investor. Rather, ETF Shares can only be purchased or redeemed directly from the issuing fund by certain authorized broker-dealers. These broker-dealers may purchase and redeem ETF Shares only in large blocks (Creation Units), usually in exchange for baskets of securities and not for cash (although some funds issue and redeem Creation Units in exchange for cash or a combination of cash and securities).

An organized secondary trading market is expected to exist for ETF Shares, unlike conventional mutual fund shares, because ETF Shares are listed for trading on a national securities exchange. Individual investors can purchase and sell ETF Shares on the secondary market through a broker. Secondary-market transactions occur not at NAV, but at market prices that are subject to change throughout the day based on the supply of and demand for ETF Shares, changes in the prices of the fund's portfolio holdings, and other factors.

The market price of ETF Shares typically will differ somewhat from the NAV of those shares. The difference between market price and NAV is expected to be small most of the time, but in times of market disruption or extreme market volatility, the difference may become significant.

How Do I Buy and Sell Vanguard ETF Shares?

ETF Shares of the Fund are listed for trading on XX. You can buy and sell ETF Shares on the secondary market in the same way you buy and sell any other exchange-traded security-through a broker. Your broker may charge a commission to execute a transaction. You will also incur the cost of the "bid-ask spread," which is the difference between the highest price a buyer is willing to pay to purchase ETF Shares (bid) and the lowest price a seller is willing to accept for ETF Shares (ask) when buying or selling shares in the secondary market. Because secondary-market transactions occur at market prices, you may pay more (premium) or less (discount) than NAV when you buy ETF Shares and receive more or less than NAV when you sell those shares. In times of severe market disruption, the bid-ask spread, and premiums/discounts can increase significantly. Unless imposed by your broker, there is no minimum dollar amount you must invest and no minimum number of ETF Shares you must buy.

Your ownership of ETF Shares will be shown on the records of the broker through which you hold the shares. Vanguard will not have any record of your ownership. Your account information will be maintained by your broker, which will provide you with account statements, confirmations of your purchases and sales of ETF Shares, and tax information. Your broker also will be responsible for ensuring that you receive income and capital gains distributions, as well as shareholder reports and other communications from the fund whose ETF Shares you own. You will receive other services (e.g., dividend reinvestment and average cost information) only if your broker offers these services.

More on the Fund and ETF Shares

This prospectus describes the principal risks you would face as a Fund shareholder. It is important to keep in mind one of the main principles of investing: generally, the higher the risk of losing money, the higher the potential reward. The reverse, also, is generally true: the lower the risk, the lower the potential reward. As you consider an investment in any fund, you should take into account your personal tolerance for fluctuations in the securities markets. Throughout the

prospectus, this   symbol is used to mark detailed information about some of the risks that you would confront as a Fund shareholder. To highlight terms and concepts important to fund investors, we have provided Plain Talk® explanations along the way. Reading the prospectus will help you decide whether the Fund is the right investment for you. We suggest that you keep this prospectus for future reference.

A Note to Investors

Vanguard ETF Shares can be purchased directly from the issuing Fund only by certain authorized broker-dealers in exchange for a basket of securities (or, in some cases, for cash or a combination of cash and securities). Individual investors generally will not be able to purchase ETF Shares directly from the Fund. Instead, these investors will purchase ETF Shares on the secondary market through a broker.

Plain Talk About Fund Expenses

All funds have operating expenses. These expenses, which are deducted from a fund's gross income, are expressed as a percentage of the net assets of the fund. Assuming that operating expenses remain as stated in the Fees and Expenses section, Vanguard 0-3 Month Treasury Bill ETF Shares' expense ratio would be 0.xx%, or $0.xx per $1,000 of average net assets.

Plain Talk About Costs of Investing

Costs are an important consideration in choosing an ETF. That is because you, as a shareholder, pay a proportionate share of the costs of operating a fund and any transaction costs incurred when the fund buys or sells securities of ETF Shares. These costs can erode a substantial portion of the gross income or the capital appreciation a fund achieves. Even seemingly small differences in expenses can, over time, have a dramatic effect on a fund's performance.

Plain Talk About Bonds and Interest Rates

As a rule, when interest rates rise, bond prices fall. The opposite is also true: bond prices go up when interest rates fall. Why do bond prices and interest rates move in opposite directions? Let's assume that you hold a bond offering a 4% yield. A year later, interest rates are on the rise and bonds of comparable quality and maturity are offered with a 5% yield. With higher-yielding bonds available, you would have trouble selling your 4% bond for the price you paid-you would probably have to lower your asking price. On the other hand, if interest rates were falling and 3% bonds were being offered, you should be able to sell your 4% bond for more than you paid.

Changes in interest rates can affect bond income as well as bond prices.

The Fund is subject to income risk, which is the chance that the Fund's income will decline because of falling interest rates. A fund's income declines when interest rates fall because the fund then must invest new cash flow and cash from maturing bonds in lower-yielding bonds. Income risk is generally high for short-term bond funds, so investors should expect the Fund's monthly income to fluctuate accordingly.

Plain Talk About Bond Maturities

A bond is issued with a specific maturity date-the date when the issuer must pay back the bond's principal (face value). Bond maturities range from less than 1 year to more than 30 years. Typically, the longer a bond's maturity, the more price risk you, as a bond investor, will face as interest rates rise-but also the higher the potential yield you could receive. Longer-term bonds are generally more suitable for investors willing to take a greater risk of price fluctuations to get higher and more stable interest income. Shorter-term bond investors should be willing to accept lower yields and greater income variability in return for less fluctuation in the value of their investment. The stated maturity of a bond may differ from the effective maturity of a bond, which takes into consideration that an action such as a call or refunding may cause bonds to be repaid before their stated maturity dates.

Plain Talk About Types of Bonds

Bonds are issued (sold) by many sources: Corporations issue corporate bonds; the federal government issues U.S. Treasury bonds; agencies of the federal government issue agency bonds; financial institutions issue asset- backed bonds; and mortgage holders issue "mortgage-backed" pass-through certificates. Each issuer is responsible for paying back the bond's initial value as well as for making periodic interest payments. Many bonds issued by government agencies and entities are neither guaranteed nor insured by the U.S. government.

Market disruptions can adversely affect local and global markets as well as normal market conditions and operations. Any such disruptions could have an adverse impact on the value of the Fund's investments and Fund performance.

Security Selection

Index sampling strategy. Because it would be very expensive and inefficient to buy and sell all bonds held in its target index-which is an indexing strategy called "full replication"-the Fund uses index "sampling" techniques to select securities. Using sophisticated quantitative and qualitative methods, the Fund's advisor generally selects a representative sample of securities that approximates the full target index in terms of key risk factors and other characteristics. These factors include duration, cash flow, quality, and callability of the underlying bonds.

The Fund seeks to track the performance of the Bloomberg 0-3M Treasury Bill Index, which includes on-the-run U.S. Treasury Bills that have a remaining maturity of less than 3 months and at least 1 month . The components of the Index are reconstituted and rebalanced on a monthly basis. The Index rebalances as a market-weighted index, and bonds may enter or fall out of the Index on a monthly basis. New securities are added to and removed from the Index in connection with the month-end index rebalancing process.

The number of bonds held by the Fund and the number of bonds in the Fund's target index were XX and XX, respectively, as of XX XX, 20XX.

Index investing and risks. The Fund is an index fund. Index funds attempt to track - not outperform - the performance of a specified market index (target index). An index is a group of securities whose overall performance is used as a standard to measure the investment performance of a particular market. Some indexes represent entire markets, such as the U.S. stock market, while others cover a segment of a market, such as short-term bonds. As an index fund, the Fund seeks to track the performance of its target index regardless of how the target index is performing. The advisor's use of an indexing, or passive, approach to select and maintain investments for the Fund means that the advisor will select securities based on their inclusion in the target index and will not use

strategies to reduce negative impacts to the Fund during periods of market volatility. As a result, the Fund's performance may be lower than it would be if the Fund were actively managed.

One cannot invest directly in an index. Instead, an index fund's advisor will typically seek to hold all, or substantially all, of the securities that make up the fund's target index (often referred to as "replicating" an index or a "full replication" approach) or a representative sample of the securities that make up a fund's target index (often referred to as "sampling" an index).

The Fund is subject to index sampling risk, which is the chance that the securities selected for the Fund, in the aggregate, will not provide investment performance matching that of the Fund's target index. Index sampling risk for the Fund is expected to be low.

As an index fund, the Fund is subject to tracking error. It is important to understand that an index fund will never perform exactly the same as its target index because, among other things, an index fund will have operating expenses and transaction costs and its target index will not. Beyond these inherent differences between the operation of an index fund and the operation of its target index, there are a variety of other factors that can cause or result in tracking error. These may include, but are not limited to:

•Price differences between the securities held by an index fund and those included in its target index

•Cash flows into or out of an index fund

•The size of an index fund

•Compliance with new or existing regulatory requirements

•Portfolio transactions carried out by an index fund's advisor to minimize the distribution of capital gains

•Changes to the underlying securities that make up an index fund's target index

•Errors made by the index provider

Tracking error risk may be heightened during times of increased market volatility or under other unusual market conditions. An index fund that samples its target index may be more likely to experience tracking error than an index fund that replicates its target index.

The Fund is subject to risks associated with the provider of its target index. The index provider determines which securities to include in the target index and how the securities are weighted. The index provider does not provide any warranty or accept any liability with respect to the quality, accuracy, or completeness of the target index or any data used to compile the target index. Under normal circumstances, the index provider will rebalance (update) the target index on a regular schedule. The index provider may rebalance the target index outside of

the regular schedule or delay or cancel a scheduled rebalance, which could result in added costs for the Fund or cause the Fund to experience tracking error. The index provider may make errors, and it is possible that such errors may not be identified by the index provider for a period of time or at all. Any gains, losses, or costs associated with or resulting from an error made by the index provider will generally be borne by the Fund and, as a result, the Fund's shareholders. Vanguard does not provide any warranty or guarantee against errors made by the index provider.

The types of financial instruments that may be purchased by the Fund are identified and explained as follows:

•U.S. government and agency bonds represent loans by investors to the U.S. Treasury or a wide variety of government agencies and instrumentalities. Securities issued by most U.S. government entities are neither guaranteed by the U.S. Treasury nor backed by the full faith and credit of the U.S. government. These entities include, among others, the Federal Home Loan Banks (FHLBs), the Federal National Mortgage Association (FNMA), and the Federal Home Loan Mortgage Corporation (FHLMC). Securities issued by the U.S. Treasury and a small number of U.S. government agencies, such as the Government National Mortgage Association (GNMA), are backed by the full faith and credit of the U.S. government. The market values of U.S. government and agency securities and U.S. Treasury securities are subject to fluctuation. The Fund may concentrate (invest over 25%) its investments in government securities.

Plain Talk About U.S. Government-Sponsored Enterprises

A variety of U.S. government-sponsored enterprises (GSEs), such as the Federal Home Loan Mortgage Corporation (FHLMC), the Federal National Mortgage Association (FNMA), and the Federal Home Loan Banks (FHLBs), issue debt and mortgage-backed securities. Although GSEs may be chartered or sponsored by acts of Congress, they are not funded by congressional appropriations. In September of 2008, the U.S. Treasury placed FNMA and FHLMC under conservatorship and appointed the Federal Housing Finance Agency (FHFA) to manage their daily operations. In addition, the U.S. Treasury entered into purchase agreements with FNMA and FHLMC to provide them with capital in exchange for senior preferred stock. Generally, a GSE's securities are neither issued nor guaranteed by the U.S. Treasury and are not backed by the full faith and credit of the U.S. government. In most cases, these securities are supported only by the credit of the GSE, standing alone. In some cases, a GSE's securities may be supported by the ability of the GSE to borrow from the U.S. Treasury or may be supported by the U.S. government in some other way. Securities issued by the Government National Mortgage Association (GNMA), however, are backed by the full faith and credit of the U.S. government.

•Cash equivalent investments is a blanket term that describes a variety of short- term fixed income investments, including money market instruments, commercial paper, bank certificates of deposit, banker's acceptances, and repurchase agreements. Repurchase agreements represent short-term (normally overnight) loans by a fund to banks or large securities dealers. Repurchase agreements can carry several risks. For instance, if the seller is unable to repurchase the securities as promised, a fund may experience a loss when trying to sell the securities to another buyer. Also, if the seller becomes insolvent, a bankruptcy court may determine that the securities do not belong to a fund and order that the securities be used to pay off the seller's debts. The Fund's advisor believes that these risks can be controlled through careful security selection and monitoring.

•Futures, options, and other derivatives are described in detail under Other Investment Policies and Risks.

Other Investment Policies and Risks

In addition to investing in bonds and other fixed income securities, the Fund may make other kinds of investments to achieve its investment objective.

The Fund may invest up to 15% of its net assets in illiquid securities. Illiquid securities are investments that a fund reasonably expects cannot be sold or disposed of in current market conditions in seven calendar days or less without the sale or disposition significantly changing the market value of the investment. Restricted securities are a special type of illiquid security; these securities have not been publicly issued and legally can be resold only to qualified buyers.

The Fund may invest a small portion of its assets in fixed income futures, which are a type of derivative, and/or shares of ETFs. These fixed income futures and ETFs typically provide returns similar to those of bonds and may purchase futures or ETFs when doing so will reduce the Fund's transaction costs, facilitate cash management, mitigate risk, or have the potential to add value because the instruments are favorably priced. Vanguard receives no additional revenue from Fund assets invested in ETF Shares of other Vanguard funds. Fund assets invested in ETF Shares of other Vanguard Funds are excluded when allocating to the Fund its share of the costs of Vanguard operations.

The Fund may invest in derivatives. In general, investments in derivatives may involve risks different from, and possibly greater than, those of investments directly in the underlying securities or assets.

Generally speaking, a derivative is a financial contract whose value is based on the value of a financial asset (such as a stock, a bond, or a currency), a physical asset (such as gold, oil, or wheat), a market index, or a reference rate. The Fund may invest in derivatives only if the expected risks and rewards of the derivatives are consistent with the investment objective, policies, strategies, and risks of the Fund as disclosed in this prospectus. In particular, derivatives will be used only when they may help the advisor to accomplish one or more of the following:

•Invest in eligible asset classes with greater efficiency and lower cost than is possible through direct investment.

•Add value when these instruments are attractively priced.

•Adjust sensitivity to changes in interest rates.

•Adjust the overall credit risk of the portfolio or actively overweight or underweight credit risk to specific bond issuers.

•Hedge foreign currency exposure.

•Hedge foreign interest rate exposure.

The Fund's derivative investments may include fixed income futures contracts; fixed income options, including options on swaps; currency swaps; foreign currency exchange forwards; interest rate swaps; total return swaps; credit default swaps; or other derivatives. Losses (or gains) involving futures contracts can sometimes be substantial-in part because a relatively small price movement in a futures contract may result in an immediate and substantial loss (or gain) for a fund. Similar risks exist for other types of derivatives.

Plain Talk About Derivatives

Derivatives can take many forms. Some forms of derivatives-such as exchange-traded futures and options on securities, commodities, or indexes- have been trading on regulated exchanges for decades. These types of derivatives are standardized contracts that can easily be bought and sold and whose market values are determined and published daily. On the other hand, non-exchange-traded derivatives-such as certain swap agreements and foreign currency exchange forward contracts-tend to be more specialized or complex and may be more difficult to accurately value.

Cash Management

The Fund's daily cash balance may be invested in Vanguard Market Liquidity Fund, a government money market fund, and/or Vanguard Municipal Low Duration Fund, a short-term municipal bond fund (each, a CMT Fund), which are low-cost money market funds. When investing in a CMT Fund, the Fund bears its proportionate share of the expenses of the CMT Fund in which it invests. Vanguard receives no additional revenue from Fund assets invested in a CMT Fund.

Redemption Requests

Methods used to meet redemption requests. Redemptions of ETF Shares are typically met through a combination of cash and securities held by the Fund; see "How Are Vanguard ETF Shares Different From Conventional Mutual Fund Shares?" If cash is used to meet redemptions, the Fund typically obtains such cash through positive cash flows or the sale of Fund holdings consistent with the Fund's investment objective and strategy. Please consult the Fund's Statement of Additional Information for further information on redemptions of ETF Shares.

Under certain circumstances, including under stressed market conditions, the Fund may borrow money (subject to certain regulatory conditions and if available under board-approved procedures) through an interfund lending facility; through a bank line-of-credit, including a joint committed credit facility; or through an uncommitted line-of-credit from Vanguard in order to meet redemption requests.

Potential redemption activity impacts. Vanguard funds can be negatively impacted by certain large redemptions. These redemptions could occur due to a single shareholder or multiple shareholders deciding to sell a large quantity of shares of a Vanguard fund or a share class of a Vanguard fund. Large redemptions can occur for many reasons, either as a result of actions taken by Vanguard or its affiliates, or as a result of events unrelated to actions taken by Vanguard or its affiliates. For example, actions taken by Vanguard could include changes to a Vanguard fund's advisor(s), portfolio manager(s), and/or the composition of its portfolio. For a Vanguard fund of funds, this could involve a withdrawal from an underlying Vanguard fund or a change in the allocation to the underlying Vanguard funds. Events unrelated to actions taken by Vanguard could include shareholders selling out of a Vanguard fund in response to market movements or regulatory changes.

A large redemption could adversely affect a Vanguard fund's liquidity and net asset value (NAV). For example, a large redemption could require a Vanguard fund's advisor(s) to sell portfolio holdings at unplanned or inopportune times. The advisor's sale of these holdings, which is a taxable event, could require a Vanguard fund to distribute any corresponding capital gains or other taxable income to the Vanguard fund's remaining shareholders; see Dividends, Capital Gains, and Taxes for additional information. The increased trading activity could also increase underlying costs for a Vanguard fund due to commissions paid by the Vanguard fund.

Temporary Investment Measures

The Fund may temporarily depart from its normal investment policies and strategies when the advisor believes that doing so is in the Fund's best interest, so long as the strategy or policy employed is consistent with the Fund's investment objective. For instance, the Fund may invest beyond its normal limits in derivatives or exchange-traded funds that are consistent with the Fund's investment objective when those instruments are more favorably priced or provide

needed liquidity, as might be the case when the Fund is transitioning assets from one advisor to another or receives large cash flows that it cannot prudently invest immediately.

In addition, the Fund may take temporary defensive positions that are inconsistent with its normal investment policies and strategies-for instance, by allocating substantial assets to cash equivalent investments or other less volatile instruments-in response to adverse or unusual market, economic, political, or other conditions. In doing so, the Fund may succeed in avoiding losses but may otherwise fail to achieve its investment objective.

Special Risks of Exchange-Traded Shares

ETF Shares are not individually redeemable. They can be redeemed with the issuing Fund at NAV only by certain authorized broker-dealers and only in large blocks known as Creation Units. Consequently, if you want to liquidate some or all of your ETF Shares, you must sell them on the secondary market at prevailing market prices.

The market price of ETF Shares may differ from NAV. Although it is expected that the market price of an ETF Share typically will approximate its NAV, there may be times when the market price and the NAV differ significantly. Thus, you may pay more (premium) or less (discount) than NAV when you buy ETF Shares on the secondary market, and you may receive more or less than NAV when you sell those shares. These discounts and premiums are likely to be greatest during times of market disruption or extreme market volatility.

Vanguard's website at vanguard.com shows the previous day's closing NAV and closing market price for the Fund. The website also discloses, in the Premium/Discount Analysis section of the Fund's Price & Performance page, how frequently the Fund traded at a premium or discount to NAV (based on closing NAVs and market prices) and the magnitudes of such premiums and discounts.

An active trading market may not exist. Although Vanguard ETF Shares are listed on a national securities exchange, it is possible that an active trading market may not be maintained. Although this could happen at any time, it is more likely to occur during times of severe market disruption. If you attempt to sell your ETF Shares when an active trading market is not functioning, you may have to sell at a significant discount to NAV. In extreme cases, you may not be able to sell your shares at all.

Trading may be halted. Trading of Vanguard ETF Shares on an exchange may be halted by the activation of individual or market wide trading halts (which halt trading for a specific period of time when the price of a particular security or overall market prices decline by a specified percentage). Trading of ETF Shares may also be halted if (1) the shares are delisted from the listing exchange without first being listed on another exchange or (2) exchange officials determine that such action is appropriate in the interest of a fair and orderly market or for the protection of investors.

A precautionary note to investment companies: The Fund's ETF Shares are issued by registered investment companies, and therefore the acquisition of such shares by other investment companies and private funds is subject to the restrictions of Section 12(d)(1) of the Investment Company Act of 1940 (the 1940 Act). SEC Rule 12d1-4 under the 1940 Act permits registered investment companies to invest in other registered investment companies beyond the limits in Section 12(d)(1), subject to certain conditions, including that funds with different investment advisors must enter into a fund of funds investment agreement.

Shareholder Rights

The Fund's Agreement and Declaration of Trust, as amended, requires a shareholder bringing a derivative action on behalf of Vanguard Institutional Index Funds (the Trust) that is subject to a pre-suit demand to collectively hold at least 10% of the outstanding shares of the Trust or at least 10% of the outstanding shares of the series or class to which the demand relates and to undertake to reimburse the Trust for the expense of any counsel or advisors used when considering the merits of the demand in the event that the board of trustees determines not to bring such action. In each case, these requirements do not apply to claims arising under the federal securities laws to the extent that any such federal securities laws, rules, or regulations do not permit such application. The Fund's Bylaws also provide that shareholders waive the right to trial by jury to the fullest extent permitted by law.

Frequent Trading and Market-Timing

Unlike frequent trading of a Vanguard fund's conventional (i.e., not exchange- traded) classes of shares, frequent trading of ETF Shares does not disrupt portfolio management or otherwise harm fund shareholders. The vast majority of trading in ETF Shares occurs on the secondary market. Because these trades do not involve the issuing fund, they do not harm the fund or its shareholders. Certain broker-dealers are authorized to purchase and redeem ETF Shares directly with the issuing fund. Because these trades typically are effected in kind (i.e., for securities and not for cash), or are assessed a transaction fee when effected in cash, they do not cause any of the harmful effects to the issuing fund (as previously noted) that may result from frequent trading. For these reasons, the board of trustees of each fund that issues ETF Shares has determined that it is not

necessary to adopt policies and procedures to detect and deter frequent trading and market-timing of ETF Shares.

Portfolio Holdings

Please consult the Fund's Statement of Additional Information or our website for a description of the policies and procedures that govern disclosure of the Fund's portfolio holdings.

Turnover Rate

Although the Fund generally seeks to invest for the long term, it may sell securities regardless of how long they have been held. In general, the greater the turnover rate, the greater the impact transaction costs will have on a fund's return. Also, funds with high turnover rates may be more likely to generate capital gains, including short-term capital gains, that must be distributed to shareholders and will be taxable to shareholders investing through a taxable account. The Fund has no operating history, and therefore has no portfolio turnover information.

The Fund and Vanguard

The Fund is a member of The Vanguard Group, Inc. (Vanguard), a family of over 200 funds. All of the funds that are members of Vanguard (other than funds of funds) share in the expenses associated with administrative services and business operations, such as personnel, office space, and equipment.

Vanguard Marketing Corporation provides marketing services to the funds. Although fund shareholders do not pay sales commissions or 12b-1 distribution fees, each fund (other than a fund of funds) or each share class of a fund (in the case of a fund with multiple share classes) pays its allocated share of the Vanguard funds' marketing costs.

Plain Talk About Vanguard's Unique Corporate Structure

Vanguard is owned jointly by the funds it oversees and thus indirectly by the shareholders in those funds. Most other mutual funds are operated by management companies that are owned by third parties-either public or private stockholders-and not by the funds they serve.

Investment Advisor

The Vanguard Group, Inc., P.O. Box 2600, Valley Forge, PA 19482, which began operations in 1975, serves as advisor to the Fund through its Fixed Income Group. As of xx, Vanguard served as advisor for approximately $xx trillion in assets. Vanguard provides investment advisory services to the Fund pursuant to the Funds' Service Agreement and subject to the supervision and oversight of the trustees and officers of the Fund.

Although the Fund is managed solely by Vanguard, the Fund reserves the right to utilize a multi-manager approach in the future. Under the terms of an SEC exemption, the Fund's board of trustees may, without prior approval from shareholders, change the terms of an advisory agreement with a third-party investment advisor or hire a new third-party investment advisor-either as a replacement for an existing advisor or as an additional advisor. Any significant change in the Fund's advisory arrangements will be communicated to shareholders in writing. As the Fund's sponsor and overall manager, Vanguard may provide investment advisory services to the Fund at any time. Vanguard may also recommend to the board of trustees that an advisor be hired, terminated, or replaced or that the terms of an existing advisory agreement be revised. The Fund has filed an application seeking a similar SEC exemption with respect to investment advisors that are wholly owned subsidiaries of Vanguard. If the exemption is granted, the Fund may rely on the new SEC relief.

For a discussion of why the board of trustees approved the Fund's investment advisory arrangement, see the Fund's first Financial Statements and Other Information following the Fund's commencement of operations.

The manager primarily responsible for the day-to-day management of the Fund is:

Joshua C. Barrickman, CFA, Principal of Vanguard and co-head of Vanguard's Fixed Income Indexing Americas. He has been with Vanguard since 1998, has worked in investment management since 1999, has managed investment portfolios since 2005, and has managed the Fund since its inception in xx. Education: B.S., Ohio Northern University; M.B.A., Lehigh University.

The Fund's Statement of Additional Information provides information about the portfolio manager's compensation, other accounts under management, and ownership of shares of the Fund.

Dividends, Capital Gains, and Taxes

Fund Distributions

The Fund distributes to shareholders virtually all of its net income (interest less expenses) as well as any net short-term or long-term capital gains realized from the sale of its holdings. From time to time, the Fund may also make distributions that are treated as a return of capital. Income dividends generally are declared monthly and distributed monthly; capital gains distributions, if any, generally occur annually in December. In addition, the Fund may occasionally make a supplemental distribution at some other time during the year.

Plain Talk About Distributions

As a shareholder, you are entitled to your portion of a fund's income from interest as well as capital gains from the fund's sale of investments. Income consists of interest the fund earns from its money market and bond investments. Capital gains are realized whenever the fund sells securities for higher prices than it paid for them. These capital gains are either short-term or long-term, depending on whether the fund held the securities for one year or less or for more than one year.

Reinvestment of Distributions

In order to reinvest dividend and capital gains distributions, investors in the Fund must hold their shares at a broker that offers a reinvestment service. This can be the broker's own service or a service made available by a third party, such as the broker's outside clearing firm or the Depository Trust Company (DTC). If a reinvestment service is available, distributions of income and capital gains can automatically be reinvested in additional whole and fractional ETF Shares of the Fund. If a reinvestment service is not available, investors will receive their distributions in cash. To determine whether a reinvestment service is available

and whether there is a commission or other charge for using this service, consult your broker.

As with all exchange-traded funds, reinvestment of dividend and capital gains distributions in additional ETF Shares will occur two business days or more after the ex-dividend date (the date when a distribution of dividends or capital gains is deducted from the price of the Fund's shares). The exact number of days depends on your broker. During that time, the amount of your distribution will not be invested in the Fund and therefore will not share in the Fund's income, gains, and losses.

Basic Tax Points

Investors in taxable accounts should be aware of the following basic federal income tax points:

•Distributions are taxable to you whether or not you reinvest these amounts in additional ETF Shares.

•Distributions declared and recorded in December-if paid to you by the end of January-are taxable as if received in December.

•Any income dividend distribution or short-term capital gains distribution that you receive is taxable to you as ordinary income.

•Any distribution of net long-term capital gains is taxable to you as long-term capital gains, no matter how long you have owned ETF Shares.

•Capital gains distributions can occur when the Fund sells assets at a gain. Capital gains distributions vary from year to year as a result of the Fund's investment activities and cash flows, including those due to redemption activity by Fund shareholders.

•Capital gains distributions may occur if Vanguard makes changes that would impact the Fund directly or indirectly, including if Vanguard makes changes to the Fund's portfolio or to any other Vanguard fund or product that would involve the redemption of shares of the Fund and the related sale of the Fund's investments.

•Your cost basis in the Fund will be decreased by the amount of any return of capital that you receive. This, in turn, will affect the amount of any capital gain or loss that you realize when selling your ETF Shares.

•Return of capital distributions generally are not taxable to you until your cost basis has been reduced to zero. If your cost basis is at zero, return of capital distributions will be treated as capital gains.

•A sale of ETF Shares is a taxable event. This means that you may have a capital gain to report as income, or a capital loss to report as a deduction, when you complete your tax return.

Individuals, trusts, and estates whose income exceeds certain threshold amounts are subject to a 3.8% Medicare contribution tax on "net investment income." Net investment income takes into account distributions paid by the Fund and capital gains from any sale of ETF Shares.

Income dividends and capital gains distributions that you receive, as well as your gains or losses from any sale of ETF Shares, may be subject to state and local

income taxes. Depending on your state's rules, however, any dividends attributable to interest earned on direct obligations of the U.S. government may be exempt from state and local taxes. Vanguard will notify you each year how much, if any, of your dividends may qualify for this exemption.

This prospectus provides general tax information only. If you are investing through

atax-advantaged account, such as an IRA or an employer-sponsored retirement or savings plan, special tax rules apply. Please consult your tax advisor for detailed information about any tax consequences for you.

Share Price and Market Price

Share price, also known as NAV, is typically calculated as of the close of regular trading on the New York Stock Exchange (NYSE), generally 4 p.m., Eastern time, on each day that the NYSE is open for business (a business day). In the rare event the NYSE experiences unanticipated disruptions and is unavailable at the close of the trading day, NAVs will be calculated as of the close of regular trading on the Nasdaq (or another alternate exchange if the Nasdaq is unavailable, as determined at Vanguard's discretion), generally 4 p.m., Eastern time. The NAV per share is computed by dividing the total assets, minus liabilities, of the Fund by the number of Fund shares outstanding. On U.S. holidays or other days when the NYSE is closed, the NAV is not calculated, and the Fund does not sell or redeem shares. However, on those days the value of the Fund's assets may be affected to the extent that the Fund holds securities that change in value on those days (such as foreign securities that trade on foreign markets that are open).

Remember: If you buy or sell ETF Shares on the secondary market, you will pay or receive the market price, which may be higher or lower than NAV. Your transaction will be priced at NAV only if you purchase or redeem your ETF Shares in Creation Unit blocks (an option available only to certain authorized broker- dealers).

Debt securities held by a Vanguard fund are valued based on information furnished by an independent pricing service or market quotations, and are priced at fair value (the amount that the owner might reasonably expect to receive upon the current sale of the security).

The values of any foreign securities held by a fund are converted into U.S. dollars using an exchange rate obtained from an independent third party as of the close of regular trading on the NYSE. The values of any mutual fund shares, including institutional money market fund shares, held by a fund are based on the NAVs of the shares. The values of any ETF shares or closed-end fund shares held by a fund are based on the market value of the shares.

A fund also may use fair-value pricing on bond market holidays when the fund is open for business (such as Columbus Day and Veterans Day). Fair-value prices are determined by Vanguard according to procedures adopted by the board of trustees. When fair-value pricing is employed, the prices of securities used by a fund to calculate the NAV may differ from quoted or published prices for the same securities.

The Fund has authorized certain financial intermediaries and their designees, and may from time to time, authorize certain funds of funds for which Vanguard serves as the investment advisor (Vanguard Funds of Funds), to accept orders to buy or sell fund shares on its behalf. The Fund will be deemed to receive an order when accepted by the financial intermediary, its designee, or one of the Vanguard Funds of Funds, and the order will receive the NAV next computed by the Fund after such acceptance.

Vanguard's website will show the previous day's closing NAV and closing market price for the Fund's ETF Shares.

Additional Information

The Fund's Bylaws designate Delaware courts as the sole and exclusive forum for certain claims against or related to the Trust, a trustee, an officer, or other employee of the Trust, provided that, unless the Trust otherwise consents in writing, the U.S. Federal District Courts be the sole and exclusive forum for the resolution of complaints under the Securities Act of 1933 or the 1940 Act. These provisions may limit a shareholder's ability to bring a claim in a different forum and may result in increased shareholder costs in pursuing such a claim.

Certain affiliates of the Fund and the advisor may purchase and resell ETF Shares pursuant to the prospectus.

CGS identifiers have been provided by CUSIP Global Services, managed on behalf of the American Bankers Association by Standard & Poor's Financial Services, LLC, and are not for use or dissemination in a manner that would serve as a substitute for any CUSIP service. The CUSIP Database, © 2024 American Bankers Association. "CUSIP" is a registered trademark of the American Bankers Association.

CFA® is a registered trademark owned by CFA Institute.

"Bloomberg®" and Bloomberg 0-3M Treasury Bill Index (the Index) are service marks of Bloomberg Finance L.P. and its affiliates, including Bloomberg Index Services Limited ("BISL"), the administrator of the index (collectively, "Bloomberg"), and have been licensed for use for certain purposes by Vanguard.

Vanguard 0-3 Month Treasury Bill ETF (the Fund) is not sponsored, endorsed, sold or promoted by Bloomberg. Bloomberg does not make any representation or warranty, express or implied, to the owners of or counterparties to the Fund or any member of the public regarding the advisability of investing in securities or commodities generally or in the Fund particularly. The only relationship of Bloomberg to Vanguard is the licensing of certain trademarks, trade names and service marks and of the Index, which are determined, composed and calculated by BISL without regard to Vanguard or the Fund. Bloomberg has no obligation to take the needs of Vanguard or the owners of the Fund into consideration in determining, composing or calculating the Index. Bloomberg is not responsible for and has not participated in the determination of the timing, price, or quantities of the Fund to be issued. Bloomberg shall not have any obligation or

liability, including, without limitation, to customers of the Fund, in connection with the administration, marketing or trading of the Fund.

BLOOMBERG DOES NOT GUARANTEE THE ACCURACY AND/OR THE COMPLETENESS OF THE INDEX OR ANY DATA RELATED THERETO AND SHALL HAVE NO LIABILITY FOR ANY ERRORS, OMISSIONS OR INTERRUPTIONS THEREIN. BLOOMBERG DOES NOT MAKE ANY WARRANTY, EXPRESS OR IMPLIED, AS TO RESULTS TO BE OBTAINED BY VANGUARD, OWNERS OF THE FUND OR ANY OTHER PERSON OR ENTITY FROM THE USE OF THE INDEX OR ANY DATA RELATED THERETO. BLOOMBERG DOES NOT MAKE ANY EXPRESS OR IMPLIED WARRANTIES AND EXPRESSLY DISCLAIMS ALL WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE OR USE WITH RESPECT TO THE INDEX OR ANY DATA RELATED THERETO. WITHOUT LIMITING ANY OF THE FOREGOING, TO THE MAXIMUM EXTENT ALLOWED BY LAW, BLOOMBERG, ITS LICENSORS, AND ITS AND THEIR RESPECTIVE EMPLOYEES, CONTRACTORS, AGENTS, SUPPLIERS, AND VENDORS SHALL HAVE NO LIABILITY OR RESPONSIBILITY WHATSOEVER FOR ANY INJURY OR DAMAGES-WHETHER DIRECT, INDIRECT, CONSEQUENTIAL, INCIDENTAL, PUNITIVE OR OTHERWISE-ARISING IN CONNECTION WITH THE FUND OR INDEX OR ANY DATA OR VALUES RELATING THERETO-WHETHER ARISING FROM THEIR NEGLIGENCE OR OTHERWISE, EVEN IF NOTIFIED OF THE POSSIBILITY THEREOF.

Glossary of Investment Terms

Authorized Participant. Institutional investors that are permitted to purchase Creation Units directly from, and redeem Creation Units directly with, the issuing fund. To be an Authorized Participant, an entity must be a participant in the Depository Trust Company and must enter into an agreement with the fund's Distributor.

Average Maturity. The average length of time until bonds held by a fund reach maturity and are repaid. In general, the longer the average maturity, the more a fund's share price fluctuates in response to changes in market interest rates. In calculating average maturity, a fund uses a bond's maturity or, if applicable, an earlier date on which the advisor believes it is likely that a maturity-shortening device (such as a call, put, refunding, prepayment, or redemption provision or an adjustable coupon rate) will cause the bond to be repaid.

Bid-Ask Spread. The difference between the highest price a buyer is willing to pay to purchase ETF Shares (bid) and the lowest price a seller is willing to accept for ETF Shares (ask) when buying or selling shares in the

secondary market.

Bond. A debt security issued by a corporation, a government, or a government agency in exchange for the money the bondholder lends it. In most instances, the issuer agrees to pay back the loan by a specific date and generally to make regular interest payments until that date.

Bloomberg 0-3 Month Treasury Bill Index. An index that includes both on-the- run (those newly issued) US Treasury Bills and those that have rolled down into the index's maturity range.

Capital Gains Distributions. Payments to fund shareholders of gains realized on securities that a fund has sold at a profit, minus any realized losses.

Cash Equivalent Investments. Cash deposits, short-term bank deposits, and money market instruments that include U.S. Treasury bills and notes, bank certificates of deposit (CDs), repurchase agreements, commercial paper, and banker's acceptances.

Corporate Bond. An IOU issued by a business that wants to borrow money. As with other types of bonds, the issuer promises to repay the borrowed money by a specific date and generally to make interest payments in the meantime.

Coupon Rate. The interest rate paid by the issuer of a debt security until its maturity. It is expressed as an annual percentage of the face value of the security.

Creation Unit. A large block of a specified number of ETF Shares. Certain broker- dealers known as "Authorized Participants" may purchase and redeem ETF Shares from the issuing fund in Creation Unit size blocks.

Dividend Distributions. Payments to fund shareholders of income from interest or dividends generated by a fund's investments.

Ex-Dividend Date. The date when a distribution of dividends and/or capital gains is deducted from the share price of a mutual fund, ETF, or stock. On the ex- dividend date, the share price drops by the amount of the distribution per share (plus or minus any market activity).

Expense Ratio. A fund's total annual operating expenses expressed as a percentage of the fund's average net assets. The expense ratio includes management and administrative expenses, but it does not include the transaction costs of buying and selling portfolio securities.

Face Value. The amount to be paid at a bond's maturity; also known as the par value or principal.

Fixed Income Security. An investment, such as a bond, representing a debt that must be repaid by a specified date, and on which the borrower may pay a fixed, variable, or floating rate of interest.

Inception Date. The date on which the assets of a fund are first invested in accordance with the fund's investment objective. For funds with a subscription period, the inception date is the day after that period ends. Investment performance is generally measured from the inception date.

Investment-Grade Bond. A debt security whose credit quality is considered by independent bond rating agencies, or through independent analysis conducted by a fund's advisor, to be sufficient to ensure timely payment of principal and interest under current economic circumstances. Debt securities rated in one of the four highest rating categories are considered investment-grade. Other debt securities may be considered by an advisor to be investment-grade.

Joint Committed Credit Facility. The Fund may participate, along with other funds managed by Vanguard, in a committed credit facility provided by a syndicate of lenders pursuant to a credit agreement that may be renewed annually; each Vanguard fund is individually liable for its borrowings, if any, under the credit facility. The amount and terms of the committed credit facility are subject to approval by the Fund's board of trustees and renegotiation with the lender syndicate on an annual basis.

Mutual Fund. An investment company that pools the money of many people and invests it in a variety of securities in an effort to achieve a specific objective over time.

New York Stock Exchange (NYSE). A stock exchange based in New York City that is open for regular trading on business days, Monday through Friday, from 9:30 a.m. to 4 p.m., Eastern time.

Return of Capital. A return of capital occurs when a fund's distributions exceed its earnings in a fiscal year. A return of capital is a return of all or part of your original investment or amounts paid in excess of your original investment in a fund. In general, a return of capital reduces your cost basis in a fund's shares and is not taxable to you until your cost basis has been reduced to zero.

Principal. The face value of a debt instrument or the amount of money put into an investment.

Securities. Stocks, bonds, money market instruments, and other investments.

Total Return. A percentage change, over a specified time period, in a fund's net asset value, assuming the reinvestment of all distributions of dividends and capital gains.

Volatility. The fluctuations in value of a mutual fund or other security. The greater a fund's volatility, the wider the fluctuations in its returns.

Yield. Income (interest or dividends) earned by an investment, expressed as a percentage of the investment's price.

Subject to Completion

Preliminary Statement of Additional Information

Dated November 22, 2024

Information contained in this Statement of Additional Information is subject to completion or amendment. A registration statement for Vanguard Institutional Index Funds to add the new Series, Vanguard 0-3 Month Treasury Bill ETF and Vanguard Ultra-Short Treasury ETF, has been filed with the U.S. Securities and Exchange Commission but has not yet become effective.

Shares of Vanguard 0-3 Month Treasury Bill ETF and Vanguard Ultra-Short Treasury ETF may not be sold, nor may offers to buy be accepted, prior to the time the registration statement becomes effective. This Statement of Additional Information is not a prospectus.

PART B

VANGUARD® INSTITUTIONAL INDEX FUNDS

STATEMENT OF ADDITIONAL INFORMATION

xx, 20xx

This Statement of Additional Information is not a prospectus but should be read in conjunction with a Fund's current prospectus (dated xx, 20xx). To obtain, without charge, a prospectus, or, when available, the report to shareholders, or the Fund's financial statements, please contact The Vanguard Group, Inc. (Vanguard).

Phone: Institutional Investor Information Department at 888-809-8102

Online: vanguard.com

TABLE OF CONTENTS

Description of Bond Ratings ...……………………………………………………………………………………………………………………….. B-XX

Appendix A……………………………………………………………………………………………………………………………………………….. B-XX

DESCRIPTION OF THE TRUST

Vanguard Institutional Index Funds (the Trust) currently offers the following funds and share classes (identified by ticker symbol):

1Individually, a class; collectively, the classes.

2Individually, a Fund; collectively, the Funds.

3Exchange: XX

This Statement of Additional Information relates only to Vanguard 0-3 Month Treasury Bill ETF and Vanguard Ultra- Short Treasury ETF (each, a Fund, and together, the Funds). A separate Statement of Additional Information dated April 26, 2024, which relates to the Trust's other funds, can be obtained free of charge by contacting Vanguard.

The Trust has the ability to offer additional funds or classes of shares. There is no limit on the number of full and fractional shares that may be issued for a single fund or class of shares.

Throughout this document, any references to "class" apply only to the extent a Fund issues multiple classes.

Organization

The Trust was organized as a Pennsylvania business trust in 1990 and was reorganized as a Delaware statutory trust in 1998. The Trust is registered with the United States Securities and Exchange Commission (SEC) under the Investment Company Act of 1940 (the 1940 Act) as an open-end management investment company. The Funds are classified as diversified within the meaning of the 1940 Act.

Service Providers

Custodian. State Street Bank and Trust Company, One Congress Street, Suite 1, Boston, MA 02114, serve as the Funds' custodian. The custodian is responsible for maintaining the Funds' assets, keeping all necessary accounts and records of Fund assets, and appointing any foreign subcustodians or foreign securities depositories.

Independent Registered Public Accounting Firm. xx, serves as the Funds' independent registered public accounting firm. The independent registered public accounting firm audits the Funds' annual financial statements and provides other related services.

Transfer and Dividend-Paying Agent. The Funds' transfer agent and dividend-paying agent is Vanguard, P.O. Box 2600, Valley Forge, PA 19482.

Characteristics of the Funds' Shares

Restrictions on Holding or Disposing of Shares. There are no restrictions on the right of shareholders to retain or dispose of a Fund's shares, other than those described in the Fund's current prospectus and elsewhere in this Statement of Additional Information. Each Fund or class may be terminated by reorganization into another mutual fund or class or by liquidation and distribution of the assets of the Fund or class. Unless terminated by reorganization or liquidation, each Fund and share class will continue indefinitely.

Shareholder Liability. The Trust is organized under Delaware law, which provides that shareholders of a statutory trust are entitled to the same limitations of personal liability as shareholders of a corporation organized under Delaware law. This means that a shareholder of a Fund generally will not be personally liable for payment of the Fund's debts. Some state courts, however, may not apply Delaware law on this point. We believe that the possibility of such a situation arising is remote.

Dividend Rights. The shareholders of each class of a Fund are entitled to receive any dividends or other distributions declared by the Fund for each such class. No shares of a Fund have priority or preference over any other shares of the Fund with respect to distributions. Distributions will be made from the assets of the Fund and will be paid ratably to all shareholders of a particular class according to the number of shares of the class held by shareholders on the record date. The amount of dividends per share may vary between separate share classes of the Fund based upon differences in the net asset values of the different classes and differences in the way that expenses are allocated between share classes pursuant to a multiple class plan approved by the Fund's board of trustees.

Voting Rights. Shareholders are entitled to vote on a matter if (1) the matter concerns an amendment to the Declaration of Trust that would adversely affect to a material degree the rights and preferences of the shares of a Fund or any class;

(2)the trustees determine that it is necessary or desirable to obtain a shareholder vote; (3) a merger or consolidation, share conversion, share exchange, or sale of assets is proposed and a shareholder vote is required by the 1940 Act to approve the transaction; or (4) a shareholder vote is required under the 1940 Act. The 1940 Act requires a shareholder vote under various circumstances, including to elect or remove trustees upon the written request of shareholders representing 10% or more of a Fund's net assets, to change any fundamental policy of a Fund (please see Fundamental Policies), and to enter into certain merger transactions. Unless otherwise required by applicable law, shareholders of a Fund receive one vote for each dollar of net asset value owned on the record date and a fractional vote for each fractional dollar of net asset value owned on the record date. However, only the shares of a Fund or the

class affected by a particular matter are entitled to vote on that matter. In addition, each class has exclusive voting rights on any matter submitted to shareholders that relates solely to that class, and each class has separate voting rights on any matter submitted to shareholders in which the interests of one class differ from the interests of another. Voting rights are noncumulative and cannot be modified without a majority vote by the shareholders.

Liquidation Rights. In the event that a Fund is liquidated, shareholders will be entitled to receive a pro rata share of the Fund's net assets. In the event that a class of shares is liquidated, shareholders of that class will be entitled to receive a pro rata share of the Fund's net assets that are allocated to that class. Shareholders may receive cash, securities, or a combination of the two.

Preemptive Rights. There are no preemptive rights associated with the Funds' shares.

Conversion Rights. There are no conversion rights associated with Vanguard 0-3 Month Treasury Bill ETF and Vanguard Ultra-Short Treasury ETF.

Redemption Provisions. Each Fund's redemption provisions are described in its current prospectus and elsewhere in this Statement of Additional Information.

Sinking Fund Provisions. The Funds have no sinking fund provisions.

Calls or Assessment. Each Fund's shares, when issued, are fully paid and non-assessable.

Shareholder Rights. Any limitations on a shareholder's right to bring an action do not apply to claims arising under the federal securities laws to the extent that any such federal securities laws, rules, or regulations do not permit such limitations. Each Trust's bylaws place limitations on the forum in which certain claims against or related to the Trust, a trustee, officer, or other employee of the Trust may be heard. The bylaws also provide that shareholders waive the right to trial by jury to the fullest extent permitted by law.

Tax Status of the Funds

Each Fund expects to qualify each year for treatment as a "regulated investment company" under Subchapter M of the Internal Revenue Code of 1986, as amended (the IRC). This special tax status means that the Fund will not be liable for federal tax on income and capital gains distributed to shareholders. In order to preserve its tax status, each Fund must comply with certain requirements relating to the source of its income and the diversification of its assets. If a Fund fails to meet these requirements in any taxable year, the Fund will, in some cases, be able to cure such failure, including by paying a fund-level tax, paying interest, making additional distributions, and/or disposing of certain assets. If the Fund is ineligible to or otherwise does not cure such failure for any year, it will be subject to tax on its taxable income at corporate rates, and all distributions from earnings and profits, including any distributions of net tax-exempt income and net long- term capital gains, will be taxable to shareholders as ordinary income. In addition, a Fund could be required to recognize unrealized gains, pay substantial taxes and interest, and make substantial distributions before regaining its tax status as a regulated investment company.

Dividends received and distributed by each Fund on shares of stock of domestic corporations (excluding Real Estate Investment Trusts (REITs)) and certain foreign corporations generally may be eligible to be reported by the Funds, and treated by individual shareholders, as "qualified dividend income" taxed at long-term capital gain rates instead of at higher ordinary income tax rates. Individuals must satisfy holding period and other requirements in order to be eligible for such treatment. Also, distributions attributable to income earned on a Fund's securities lending transactions, including substitute dividend payments received by a Fund with respect to a security out on loan, will not be eligible for treatment as qualified dividend income.

Taxable ordinary dividends received and distributed by each Fund on its REIT holdings may be eligible to be reported by the Fund, and treated by individual shareholders, as "qualified REIT dividends" that are eligible for a 20% deduction on its federal income tax returns. Individuals must satisfy holding period and other requirements in order to be eligible for this deduction. Without further legislation, the deduction would sunset in 2025. Shareholders should consult their own tax professionals concerning their eligibility for this deduction.

Dividends received and distributed by each Fund on shares of stock of domestic corporations (excluding REITs) may be eligible for the dividends-received deduction applicable to corporate shareholders. Corporations must satisfy certain requirements in order to claim the deduction. Also, distributions attributable to income earned on a Fund's securities lending transactions, including substitute dividend payments received by a Fund with respect to a security out on loan, will not be eligible for the dividends-received deduction.

Each Fund may declare a capital gain dividend consisting of the excess (if any) of net realized long-term capital gains over net realized short-term capital losses. Net capital gains for a fiscal year are computed by taking into account any capital loss carryforwards of the Fund. Capital losses may be carried forward indefinitely and retain their character as either short-term or long-term.

FUNDAMENTAL POLICIES

Each Fund is subject to the following fundamental investment policies, which cannot be changed in any material way without the approval of the holders of a majority of the Fund's shares. For these purposes, a "majority" of shares means shares representing the lesser of (1) 67% or more of the Fund's net assets voted, so long as shares representing more than 50% of the Fund's net assets are present or represented by proxy or (2) more than 50% of the Fund's net assets.

Borrowing. Each Fund may borrow money only as permitted by the 1940 Act or other governing statute, by the Rules thereunder, or by the SEC or other regulatory agency with authority over the Fund.

Commodities. Each Fund may invest in commodities only as permitted by the 1940 Act or other governing statute, by the Rules thereunder, or by the SEC or other regulatory agency with authority over the Fund.

Industry Concentration. Each Fund will not concentrate its investments in the securities of issuers whose principal business activities are in the same industry or group of industries, except as may be necessary to approximate the composition of its target index.

Loans. Each Fund may make loans to another person only as permitted by the 1940 Act or other governing statute, by the Rules thereunder, or by the SEC or other regulatory agency with authority over the Fund.

Real Estate. Each Fund may not invest directly in real estate unless it is acquired as a result of ownership of securities or other instruments. This restriction shall not prevent a Fund from investing in securities or other instruments (1) issued by companies that invest, deal, or otherwise engage in transactions in real estate or (2) backed or secured by real estate or interests in real estate.

Senior Securities. Each Fund may not issue senior securities except as permitted by the 1940 Act or other governing statute, by the Rules thereunder, or by the SEC or other regulatory agency with authority over the Fund.

Underwriting. Each Fund may not act as an underwriter of another issuer's securities, except to the extent that the Fund may be deemed to be an underwriter within the meaning of the Securities Act of 1933 (the 1933 Act), in connection with the purchase and sale of portfolio securities.

Compliance with the fundamental policies previously described is generally measured at the time the securities are purchased. Unless otherwise required by the 1940 Act (as is the case with borrowing), if a percentage restriction is adhered to at the time the investment is made, a later change in percentage resulting from a change in the market value of assets will not constitute a violation of such restriction. All fundamental policies must comply with applicable regulatory requirements. For more details, see Investment Strategies, Risks, and Nonfundamental Policies.

None of these policies prevents the Funds from having an ownership interest in Vanguard. As a part owner of Vanguard, each Fund may own securities issued by Vanguard, make loans to Vanguard, and contribute to Vanguard's costs or other financial requirements. See Management of the Funds for more information.

INVESTMENT STRATEGIES, RISKS, AND NONFUNDAMENTAL POLICIES

Some of the investment strategies and policies described on the following pages and in each Fund's prospectus set forth percentage limitations on a Fund's investment in, or holdings of, certain securities or other assets. Unless otherwise required by law, compliance with these strategies and policies will be determined immediately after the acquisition of such securities or assets by the Fund. Subsequent changes in values, net assets, or other circumstances will not be considered when determining whether the investment complies with the Fund's investment strategies and policies.

The following investment strategies, risks, and policies supplement each Fund's investment strategies, risks, and policies set forth in the prospectus. With respect to the different investments discussed as follows, a Fund may acquire such investments to the extent consistent with its investment strategies and policies.

Borrowing. A fund's ability to borrow money is limited by its investment policies and limitations; by the 1940 Act; and by applicable exemptions, no-action letters, interpretations, and other pronouncements issued from time to time by the SEC and its staff or any other regulatory authority with jurisdiction. Under the 1940 Act, a fund is required to maintain continuous asset coverage (i.e., total assets including borrowings, less liabilities exclusive of borrowings) of 300% of the amount borrowed, with an exception for borrowings not in excess of 5% of the fund's total assets (at the time of borrowing) made for temporary or emergency purposes. Any borrowings for temporary purposes in excess of 5% of the fund's total assets must maintain continuous asset coverage. If the 300% asset coverage should decline as a result of market fluctuations or for other reasons, a fund may be required to sell some of its portfolio holdings within three days (excluding Sundays and holidays) to reduce the debt and restore the 300% asset coverage, even though it may be disadvantageous from an investment standpoint to sell securities at that time.

Borrowing will tend to exaggerate the effect on net asset value of any increase or decrease in the market value of a fund's portfolio. Money borrowed will be subject to interest costs that may or may not be recovered by earnings on the securities purchased with the proceeds of such borrowing. A fund also may be required to maintain minimum average balances in connection with a borrowing or to pay a commitment or other fee to maintain a line of credit; either of these requirements would increase the cost of borrowing over the stated interest rate.

A borrowing transaction will not be considered to constitute the issuance, by a fund, of a "senior security," as that term is defined in Section 18(g) of the 1940 Act, and therefore such transaction will not be subject to the 300% asset coverage requirement otherwise applicable to borrowings by a fund, if the fund complies with Rule 18f-4 under the 1940 Act.

Common Stock. Common stock represents an equity or ownership interest in an issuer. Common stock typically entitles the owner to vote on the election of directors and other important matters, as well as to receive dividends on such stock. In the event an issuer is liquidated or declares bankruptcy, the claims of owners of bonds, other debt holders, and owners of preferred stock take precedence over the claims of those who own common stock.

Convertible Securities. Convertible securities are hybrid securities that combine the investment characteristics of bonds and common stocks. Convertible securities typically consist of debt securities or preferred stock that may be converted (on a voluntary or mandatory basis) within a specified period of time (normally for the entire life of the security) into a certain amount of common stock or other equity security of the same or a different issuer at a predetermined price. Convertible securities also include debt securities with warrants or common stock attached and derivatives combining the features of debt securities and equity securities. Other convertible securities with features and risks not specifically referred to herein may become available in the future. Convertible securities involve risks similar to those of both fixed income and equity securities. In a corporation's capital structure, convertible securities are senior to common stock but are usually subordinated to senior debt obligations of the issuer.

The market value of a convertible security is a function of its "investment value" and its "conversion value." A security's "investment value" represents the value of the security without its conversion feature (i.e., a nonconvertible debt security). The investment value may be determined by reference to its credit quality and the current value of its yield to maturity or probable call date. At any given time, investment value is dependent upon such factors as the general level of interest rates, the yield of similar nonconvertible securities, the financial strength of the issuer, and the seniority of the security in the issuer's capital structure. A security's "conversion value" is determined by multiplying the number of shares the holder is entitled to receive upon conversion or exchange by the current price of the underlying security. If the conversion value of a convertible security is significantly below its investment value, the convertible security will trade like nonconvertible debt or preferred stock and its market value will not be influenced greatly by fluctuations in the market price of the underlying security. In that circumstance, the convertible security takes on the characteristics of a bond, and its price moves in the opposite direction from interest rates. Conversely, if the conversion value of a

convertible security is near or above its investment value, the market value of the convertible security will be more heavily influenced by fluctuations in the market price of the underlying security. In that case, the convertible security's price may be as volatile as that of common stock. Because both interest rates and market movements can influence its value, a convertible security generally is not as sensitive to interest rates as a similar debt security, nor is it as sensitive to changes in share price as its underlying equity security. Convertible securities are often rated below investment-grade or are not rated, and they are generally subject to a high degree of credit risk.

Although all markets are prone to change over time, the generally high rate at which convertible securities are retired (through mandatory or scheduled conversions by issuers or through voluntary redemptions by holders) and replaced with newly issued convertible securities may cause the convertible securities market to change more rapidly than other markets. For example, a concentration of available convertible securities in a few economic sectors could elevate the sensitivity of the convertible securities market to the volatility of the equity markets and to the specific risks of those sectors. Moreover, convertible securities with innovative structures, such as mandatory-conversion securities and equity- linked securities, have increased the sensitivity of the convertible securities market to the volatility of the equity markets and to the special risks of those innovations, which may include risks different from, and possibly greater than, those associated with traditional convertible securities. A convertible security may be subject to redemption at the option of the issuer at a price set in the governing instrument of the convertible security. If a convertible security held by a fund is subject to such redemption option and is called for redemption, the fund must allow the issuer to redeem the security, convert it into the underlying common stock, or sell the security to a third party.

Cybersecurity Risks. A cybersecurity incident could subject the Vanguard funds, their advisors, and/or their third-party service providers to operational and financial risks. Cybersecurity incidents typically result from a deliberate attack, which could take multiple forms (e.g., phishing, malware, ransomware, or denial-of-service attacks), or wrongdoing by an authorized individual. In either case, sensitive assets, information, or data could fall into the hands of unauthorized individuals and potentially cause operational disruption. To prevent or reduce the impact of a cybersecurity incident, Vanguard has implemented controls, such as technological safeguards and business continuity plans. Cybersecurity risks are also present for third-party service providers (such as investment advisors, transfer agents, and custodians) that support the Vanguard funds. Vanguard has processes for assessing the cybersecurity programs implemented by a fund's third-party service providers. These processes help reduce the risk of potential incidents that could impact a Vanguard fund and/or its shareholders.

Despite the measures described above, a cybersecurity incident could still disrupt business operations, which could affect a fund and/or its shareholders. Examples of impacts which might occur as a result of a cybersecurity incident include: a fund being unable to calculate its net asset value (NAV) or process transactions, fund shareholders being unable to place transactions or otherwise conduct business with Vanguard, or a fund being unable to safeguard its data or the personal information of its shareholders.

Depositary Receipts. Depositary receipts (also sold as participatory notes) are securities that evidence ownership interests in a security or a pool of securities that have been deposited with a "depository." Depositary receipts may be sponsored or unsponsored and include American Depositary Receipts (ADRs), European Depositary Receipts (EDRs), and Global Depositary Receipts (GDRs). For ADRs, the depository is typically a U.S. financial institution, and the underlying securities are issued by a foreign issuer. For other depositary receipts, the depository may be a foreign or a U.S. entity, and the underlying securities may have a foreign or a U.S. issuer. Depositary receipts will not necessarily be denominated in the same currency as their underlying securities. Generally, ADRs are issued in registered form, denominated in U.S. dollars, and designed for use in the U.S. securities markets. Other depositary receipts, such as GDRs and EDRs, may be issued in bearer form and denominated in other currencies, and they are generally designed for use in securities markets outside the United States. Although the two types of depositary receipt facilities (sponsored and unsponsored) are similar, there are differences regarding a holder's rights and obligations and the practices of market participants.

A depository may establish an unsponsored facility without participation by (or acquiescence of) the underlying issuer; typically, however, the depository requests a letter of nonobjection from the underlying issuer prior to establishing the facility. Holders of unsponsored depositary receipts generally bear all the costs of the facility. The depository usually charges fees upon the deposit and withdrawal of the underlying securities, the conversion of dividends into U.S. dollars or other currency, the disposition of noncash distributions, and the performance of other services. The depository of an unsponsored facility frequently is under no obligation to distribute shareholder communications received from the underlying issuer or to pass through voting rights to depositary receipt holders with respect to the underlying securities.

Sponsored depositary receipt facilities are created in generally the same manner as unsponsored facilities, except that sponsored depositary receipts are established jointly by a depository and the underlying issuer through a deposit

agreement. The deposit agreement sets out the rights and responsibilities of the underlying issuer, the depository, and the depositary receipt holders. With sponsored facilities, the underlying issuer typically bears some of the costs of the depositary receipts (such as dividend payment fees of the depository), although most sponsored depositary receipt holders may bear costs such as deposit and withdrawal fees. Depositories of most sponsored depositary receipts agree to distribute notices of shareholder meetings, voting instructions, and other shareholder communications and information to the depositary receipt holders at the underlying issuer's request.

For purposes of a fund's investment policies, investments in depositary receipts will be deemed to be investments in the underlying securities. Thus, a depositary receipt representing ownership of common stock will be treated as common stock. Depositary receipts do not eliminate all of the risks associated with directly investing in the securities of foreign issuers.

Derivatives. A derivative is a financial instrument that has a value based on-or "derived from"-the values of other assets, reference rates, or indexes. Derivatives may relate to a wide variety of underlying references, such as commodities, stocks, bonds, interest rates, currency exchange rates, and related indexes. Derivatives include futures contracts and options on futures contracts, certain forward-commitment transactions, options on securities, caps, floors, collars, swap agreements, and certain other financial instruments. Some derivatives, such as futures contracts and certain options, are traded on U.S. commodity and securities exchanges, while other derivatives, such as swap agreements, may be privately negotiated and entered into in the over-the-counter market (OTC Derivatives) or may be cleared through a clearinghouse (Cleared Derivatives) and traded on an exchange or swap execution facility. As a result of the Dodd-Frank Wall Street Reform and Consumer Protection Act (the Dodd-Frank Act), certain swap agreements, such as certain standardized credit default and interest rate swap agreements, must be cleared through a clearinghouse and traded on an exchange or swap execution facility. This could result in an increase in the overall costs of such transactions. While the intent of derivatives regulatory reform is to mitigate risks associated with derivatives markets, the regulations could, among other things, increase liquidity and decrease pricing for more standardized products while decreasing liquidity and increasing pricing for less standardized products. The risks associated with the use of derivatives are different from, and possibly greater than, the risks associated with investing directly in the securities or assets on which the derivatives are based.

Derivatives may be used for a variety of purposes, including-but not limited to-hedging, managing risk, seeking to stay fully invested, seeking to reduce transaction costs, seeking to simulate an investment in equity or debt securities or other investments, and seeking to add value by using derivatives to more efficiently implement portfolio positions when derivatives are favorably priced relative to equity or debt securities or other investments. Some investors may use derivatives primarily for speculative purposes while other uses of derivatives may not constitute speculation. There is no assurance that any derivatives strategy used by a fund's advisor will succeed. The other parties to a fund's OTC Derivatives contracts (usually referred to as "counterparties") will not be considered the issuers thereof for purposes of certain provisions of the 1940 Act and the IRC, although such OTC Derivatives may qualify as securities or investments under such laws. A fund's advisor(s), however, will monitor and adjust, as appropriate, the fund's credit risk exposure to OTC Derivative counterparties.

Derivative products are highly specialized instruments that require investment techniques and risk analyses different from those associated with stocks, bonds, and other traditional investments. The use of a derivative requires an understanding not only of the underlying instrument but also of the derivative itself, without the benefit of observing the performance of the derivative under all possible market conditions.

When a fund enters into a Cleared Derivative, an initial margin deposit with a Futures Commission Merchant (FCM) is required. Initial margin deposits are typically calculated as an amount equal to the volatility in market value of a Cleared Derivative over a fixed period. If the value of the fund's Cleared Derivatives declines, the fund will be required to make additional "variation margin" payments to the FCM to settle the change in value. If the value of the fund's Cleared Derivatives increases, the FCM will be required to make additional "variation margin" payments to the fund to settle the change in value. This process is known as "marking-to-market" and is calculated on a daily basis.

For OTC Derivatives, a fund is subject to the risk that a loss may be sustained as a result of the insolvency or bankruptcy of the counterparty or the failure of the counterparty to make required payments or otherwise comply with the terms of the contract. Additionally, the use of credit derivatives can result in losses if a fund's advisor does not correctly evaluate the creditworthiness of the issuer on which the credit derivative is based.

Derivatives may be subject to liquidity risk, which exists when a particular derivative is difficult to purchase or sell. If a derivative transaction is particularly large or if the relevant market is illiquid (as is the case with certain OTC Derivatives), it may not be possible to initiate a transaction or liquidate a position at an advantageous time or price.

Derivatives may be subject to pricing or "basis" risk, which exists when a particular derivative becomes extraordinarily expensive relative to historical prices or the prices of corresponding cash market instruments. Under certain market conditions, it may not be economically feasible to initiate a transaction or liquidate a position in time to avoid a loss or take advantage of an opportunity.

Because certain derivatives have a leverage component, adverse changes in the value or level of the underlying asset, reference rate, or index can result in a loss substantially greater than the amount invested in the derivative itself. Certain derivatives have the potential for unlimited loss, regardless of the size of the initial investment. A derivative transaction will not be considered to constitute the issuance, by a fund, of a "senior security," as that term is defined in Section 18(g) of the 1940 Act, and therefore such transaction will not be subject to the 300% asset coverage requirement otherwise applicable to borrowings by a fund, if the fund complies with Rule 18f-4.

Like most other investments, derivative instruments are subject to the risk that the market value of the instrument will change in a way detrimental to a fund's interest. A fund bears the risk that its advisor will incorrectly forecast future market trends or the values of assets, reference rates, indexes, or other financial or economic factors in establishing derivative positions for the fund. If the advisor attempts to use a derivative as a hedge against, or as a substitute for, a portfolio investment, the fund will be exposed to the risk that the derivative will have or will develop imperfect or no correlation with the portfolio investment. This could cause substantial losses for the fund. Although hedging strategies involving derivative instruments can reduce the risk of loss, they can also reduce the opportunity for gain or even result in losses by offsetting favorable price movements in other fund investments. Many derivatives (in particular, OTC Derivatives) are complex and often valued subjectively. Improper valuations can result in increased cash payment requirements to counterparties or a loss of value to a fund.

On October 28, 2020, the Securities and Exchange Commission adopted new regulations governing the use of derivatives by registered investment companies ("Rule 18f-4"). The Funds were required to implement and comply with Rule 18f-4 by August 19, 2022. Rule 18f-4 imposes limits on the amount of derivatives a fund can enter into, eliminates the asset segregation framework currently used by funds to comply with Section 18 the 1940 Act, as amended, treats derivatives as senior securities, and requires funds whose use of derivatives is more than a limited specified exposure amount to establish and maintain a comprehensive derivatives risk management program and appoint a derivatives risk manager.

Each Fund intends to comply with Rule 4.5 under the Commodity Exchange Act (CEA), under which a fund may be excluded from the definition of the term Commodity Pool Operator (CPO) if the fund meets certain conditions such as limiting its investments in certain CEA-regulated instruments (e.g., futures, options, or swaps) and complying with certain marketing restrictions. Accordingly, Vanguard is not subject to registration or regulation as a CPO with respect to each Fund under the CEA. Each Fund will only enter into futures contracts and futures options that are traded on a U.S. or foreign exchange, board of trade, or similar entity or that are quoted on an automated quotation system.

Environmental, Social, and Governance (ESG) Considerations. Vanguard's Investment Stewardship Team, on behalf of the Board of Trustees of each Vanguard-advised U.S. fund, administers proxy voting for the equity holdings of the Vanguard-advised funds. The Investment Stewardship Team may engage with issuers to better understand how they are addressing material risks, including material environmental, social, or governance risks. Specifically, the Investment Stewardship Team may engage with company leaders and directors to understand how they oversee, mitigate, and disclose material risks to shareholders. With respect to material human-rights-related risks, where such matters are not addressed by applicable sanctions laws and regulations that restrict specific investments, the Investment Stewardship Team employs procedures to identify and monitor material human-rights-related risks to long-term shareholder returns at portfolio companies held by the Vanguard-advised funds and to understand how portfolio company boards are overseeing any such risks.

Exchange-Traded Funds. A fund may purchase shares of exchange-traded funds (ETFs). Typically, a fund would purchase ETF shares for the same reason it would purchase (and as an alternative to purchasing) futures contracts: to obtain exposure to all or a portion of the stock or bond market. ETF shares enjoy several advantages over futures. Depending on the market, the holding period, and other factors, ETF shares can be less costly and more tax-efficient than futures. In addition, ETF shares can be purchased for smaller sums, offer exposure to market sectors and styles for which there is no suitable or liquid futures contract, and do not involve leverage.

An investment in an ETF generally presents the same principal risks as an investment in a conventional fund (i.e., one that is not exchange-traded) that has the same investment objective, strategies, and policies. The price of an ETF can fluctuate within a wide range, and a fund could lose money investing in an ETF if the prices of the securities owned by the ETF go down. In addition, ETFs are subject to the following risks that do not apply to conventional funds: (1) the

market price of an ETF's shares may trade at a discount or a premium to their net asset value; (2) an active trading market for an ETF's shares may not develop or be maintained; and (3) trading of an ETF's shares may be halted by the activation of individual or marketwide trading halts (which halt trading for a specific period of time when the price of a particular security or overall market prices decline by a specified percentage). Trading of an ETF's shares may also be halted if the shares are delisted from the exchange without first being listed on another exchange or if the listing exchange's officials determine that such action is appropriate in the interest of a fair and orderly market or for the protection of investors.

Most ETFs are investment companies. Therefore, a fund's purchases of ETF shares generally are subject to the limitations on, and the risks of, a fund's investments in other investment companies, which are described under the heading "Other Investment Companies."

Foreign Securities. Typically, foreign securities are considered to be equity or debt securities issued by entities organized, domiciled, or with a principal executive office outside the United States, such as foreign corporations and governments. Securities issued by certain companies organized outside the United States may not be deemed to be foreign securities if the company's principal operations are conducted from the United States or when the company's equity securities trade principally on a U.S. stock exchange. Foreign securities may trade in U.S. or foreign securities markets. A fund may make foreign investments either directly by purchasing foreign securities or indirectly by purchasing depositary receipts or depositary shares of similar instruments (depositary receipts) for foreign securities. Direct investments in foreign securities may be made either on foreign securities exchanges or in the over-the-counter (OTC) markets. Investing in foreign securities involves certain special risk considerations that are not typically associated with investing in securities of U.S. companies or governments.

Because foreign issuers are not generally subject to uniform accounting, auditing, and financial reporting standards and practices comparable to those applicable to U.S. issuers, there may be less publicly available information about certain foreign issuers than about U.S. issuers. Evidence of securities ownership may be uncertain in many foreign countries. As a result, there are risks that could result in a loss to the fund, including, but not limited to, the risk that a fund's trade details could be incorrectly or fraudulently entered at the time of a transaction. Securities of foreign issuers are generally more volatile and less liquid than securities of comparable U.S. issuers, and foreign investments may be effected through structures that may be complex or confusing. In certain countries, there is less government supervision and regulation of stock exchanges, brokers, and listed companies than in the United States. The risk that securities traded on foreign exchanges may be suspended, either by the issuers themselves, by an exchange, or by government authorities, is also heightened. In addition, with respect to certain foreign countries, there is the possibility of expropriation or confiscatory taxation, political or social instability, war, terrorism, nationalization, limitations on the removal of funds or other assets, or diplomatic developments that could affect U.S. investments in those countries. Additionally, the imposition of economic or other sanctions on the United States by a foreign country, or on a foreign country or issuer by the United States, could impair a fund's ability to buy, sell, hold, receive, deliver, or otherwise transact in certain investment securities or obtain exposure to foreign securities and assets. This may negatively impact the value and/or liquidity of a fund's investments and could impair a fund's ability to meet its investment objective or invest in accordance with its investment strategy. Sanctions could also result in the devaluation of a country's currency, a downgrade in the credit ratings of a country or issuers in a country, or a decline in the value and/or liquidity of securities of issuers in that country.

Although an advisor will endeavor to achieve the most favorable execution costs for a fund's portfolio transactions in foreign securities under the circumstances, commissions and other transaction costs are generally higher than those on U.S. securities. In addition, it is expected that the custodian arrangement expenses for a fund that invests primarily in foreign securities will be somewhat greater than the expenses for a fund that invests primarily in domestic securities. Additionally, bankruptcy laws vary by jurisdiction and cash deposits may be subject to a custodian's creditors. Certain foreign governments levy withholding or other taxes against dividend and interest income from, capital gains on the sale of, or transactions in foreign securities. Although in some countries a portion of these taxes is recoverable by the fund, the nonrecovered portion of foreign withholding taxes will reduce the income received from such securities.

The value of the foreign securities held by a fund that are not U.S. dollar-denominated may be significantly affected by changes in currency exchange rates. The U.S. dollar value of a foreign security generally decreases when the value of the U.S. dollar rises against the foreign currency in which the security is denominated, and it tends to increase when the value of the U.S. dollar falls against such currency (as discussed under the heading "Foreign Securities-Foreign

Currency Transactions," a fund may attempt to hedge its currency risks). In addition, the value of fund assets may be affected by losses and other expenses incurred from converting between various currencies in order to purchase and sell foreign securities, as well as by currency restrictions, exchange control regulations, currency devaluations, and political and economic developments.

Foreign Securities-Foreign Currency Transactions. The value in U.S. dollars of a fund's non-dollar-denominated foreign securities may be affected favorably or unfavorably by changes in foreign currency exchange rates and exchange control regulations, and the fund may incur costs in connection with conversions between various currencies. To seek to minimize the impact of such factors on net asset values, a fund may engage in foreign currency transactions in connection with its investments in foreign securities. A fund will enter into foreign currency transactions only to attempt to "hedge" the currency risk associated with investing in foreign securities. Although such transactions tend to minimize the risk of loss that would result from a decline in the value of the hedged currency, they also may limit any potential gain that might result should the value of such currency increase.

Currency exchange transactions may be conducted either on a spot (i.e., cash) basis at the rate prevailing in the currency exchange market or through forward contracts to purchase or sell foreign currencies. A forward currency contract involves an obligation to purchase or sell a specific currency at a future date, which may be any fixed number of days from the date of the contract agreed upon by the parties, at a price set at the time of the contract. These contracts are entered into with large commercial banks or other currency traders who are participants in the interbank market. Currency exchange transactions also may be effected through the use of swap agreements or other derivatives.

Currency exchange transactions may be considered borrowings. A currency exchange transaction will not be considered to constitute the issuance, by a fund, of a "senior security," as that term is defined in Section 18(g) of the 1940 Act, and therefore such transaction will not be subject to the 300% asset coverage requirement otherwise applicable to borrowings by a fund, if the fund complies with Rule 18f-4.

By entering into a forward contract for the purchase or sale of foreign currency involved in underlying security transactions, a fund may be able to protect itself against part or all of the possible loss between trade and settlement dates for that purchase or sale resulting from an adverse change in the relationship between the U.S. dollar and such foreign currency. This practice is sometimes referred to as "transaction hedging." In addition, when the advisor reasonably believes that a particular foreign currency may suffer a substantial decline against the U.S. dollar, a fund may enter into a forward contract to sell an amount of foreign currency approximating the value of some or all of its portfolio securities denominated in such foreign currency. This practice is sometimes referred to as "portfolio hedging." Similarly, when the advisor reasonably believes that the U.S. dollar may suffer a substantial decline against a foreign currency, a fund may enter into a forward contract to buy that foreign currency for a fixed dollar amount.

A fund may also attempt to hedge its foreign currency exchange rate risk by engaging in currency futures, options, and "cross-hedge" transactions. In cross-hedge transactions, a fund holding securities denominated in one foreign currency will enter into a forward currency contract to buy or sell a different foreign currency (one that the advisor reasonably believes generally tracks the currency being hedged with regard to price movements). The advisor may select the tracking (or substitute) currency rather than the currency in which the security is denominated for various reasons, including in order to take advantage of pricing or other opportunities presented by the tracking currency or to take advantage of a more liquid or more efficient market for the tracking currency. Such cross-hedges are expected to help protect a fund against an increase or decrease in the value of the U.S. dollar against certain foreign currencies.

A fund may hold a portion of its assets in bank deposits denominated in foreign currencies so as to facilitate investment in foreign securities as well as protect against currency fluctuations and the need to convert such assets into U.S. dollars (thereby also reducing transaction costs). To the extent these assets are converted back into U.S. dollars, the value of the assets so maintained will be affected favorably or unfavorably by changes in foreign currency exchange rates and exchange control regulations.

Forecasting the movement of the currency market is extremely difficult. Whether any hedging strategy will be successful is highly uncertain. Moreover, it is impossible to forecast with precision the market value of portfolio securities at the expiration of a forward currency contract. Accordingly, a fund may be required to buy or sell additional currency on the spot market (and bear the expense of such transaction) if its advisor's predictions regarding the movement of foreign currency or securities markets prove inaccurate. In addition, the use of cross-hedging transactions may involve special risks and may leave a fund in a less advantageous position than if such a hedge had not been established. Because forward currency contracts are privately negotiated transactions, there can be no assurance that a fund will have flexibility to roll over a forward currency contract upon its expiration if it desires to do so. Additionally, there can be no assurance that the other party to the contract will perform its services thereunder.

Foreign Securities-Foreign Investment Companies. Some of the countries in which a fund may invest may not permit, or may place economic restrictions on, direct investment by outside investors. Fund investments in such countries may be permitted only through foreign government-approved or authorized investment vehicles, which may include other investment companies. Such investments may be made through registered or unregistered closed-end investment companies that invest in foreign securities. Investing through such vehicles may involve layered fees or expenses and may also be subject to the limitations on, and the risks of, a fund's investments in other investment companies, which are described under the heading "Other Investment Companies."

Foreign Securities-Russian Market Risk. Russia's recent launch of a large-scale invasion of Ukraine has resulted in sanctions against Russian governmental institutions, Russian entities, and Russian individuals that may result in the devaluation of Russian currency; a downgrade in the country's credit rating; a freeze of Russian foreign assets; a decline in the value and liquidity of Russian securities, properties, or interests; and other adverse consequences to the Russian economy and Russian assets. In addition, a fund's ability to price, buy, sell, receive, or deliver Russian investments has been and may continue to be impaired. These sanctions, and the resulting disruption of the Russian economy, may cause volatility in other regional and global markets and may negatively impact the performance of various sectors and industries, as well as companies in other countries, which could have a negative effect on the performance of a fund, even if the fund does not have direct exposure to securities of Russian issuers.

Futures Contracts and Options on Futures Contracts. Futures contracts and options on futures contracts are derivatives. A futures contract is a standardized agreement between two parties to buy or sell at a specific time in the future a specific quantity of a commodity at a specific price. The commodity may consist of an asset, a reference rate, or an index. A security futures contract relates to the sale of a specific quantity of shares of a single equity security or a narrow-based securities index. The value of a futures contract tends to increase and decrease in tandem with the value of the underlying commodity. The buyer of a futures contract enters into an agreement to purchase the underlying commodity on the settlement date and is said to be "long" the contract. The seller of a futures contract enters into an agreement to sell the underlying commodity on the settlement date and is said to be "short" the contract. The price at which a futures contract is entered into is established either in the electronic marketplace or by open outcry on the floor of an exchange between exchange members acting as traders or brokers. Open futures contracts can be liquidated or closed out by physical delivery of the underlying commodity or payment of the cash settlement amount on the settlement date, depending on the terms of the particular contract. Some financial futures contracts (such as security futures) provide for physical settlement at maturity. Other financial futures contracts (such as those relating to interest rates, foreign currencies, and broad-based securities indexes) generally provide for cash settlement at maturity. In the case of cash- settled futures contracts, the cash settlement amount is equal to the difference between the final settlement or market price for the relevant commodity on the last trading day of the contract and the price for the relevant commodity agreed upon at the outset of the contract. Most futures contracts, however, are not held until maturity but instead are "offset" before the settlement date through the establishment of an opposite and equal futures position.

The purchaser or seller of a futures contract is not required to deliver or pay for the underlying commodity unless the contract is held until the settlement date. However, both the purchaser and seller are required to deposit "initial margin" with a futures commission merchant (FCM) when the futures contract is entered into. Initial margin deposits are typically calculated as an amount equal to the volatility in market value of a contract over a fixed period. If the value of the fund's position declines, the fund will be required to make additional "variation margin" payments to the FCM to settle the change in value. If the value of the fund's position increases, the FCM will be required to make additional "variation margin" payments to the fund to settle the change in value. This process is known as "marking-to-market" and is calculated on a daily basis. A futures transaction will not be considered to constitute the issuance, by a fund, of a "senior security," as that term is defined in Section 18(g) of the 1940 Act, and therefore such transaction will not be subject to the 300% asset coverage requirement otherwise applicable to borrowings by a fund, if the fund complies with Rule 18f-4.

An option on a futures contract (or futures option) conveys the right, but not the obligation, to purchase (in the case of a call option) or sell (in the case of a put option) a specific futures contract at a specific price (called the "exercise" or "strike" price) any time before the option expires. The seller of an option is called an option writer. The purchase price of an option is called the premium. The potential loss to an option buyer is limited to the amount of the premium plus transaction costs. This will be the case, for example, if the option is held and not exercised prior to its expiration date. Generally, an option writer sells options with the goal of obtaining the premium paid by the option buyer. If an option sold by an option writer expires without being exercised, the writer retains the full amount of the premium. The option writer, however, has unlimited economic risk because its potential loss, except to the extent offset by the premium

received when the option was written, is equal to the amount the option is "in-the-money" at the expiration date. A call option is in-the-money if the value of the underlying futures contract exceeds the exercise price of the option. A put option is in-the-money if the exercise price of the option exceeds the value of the underlying futures contract. Generally, any profit realized by an option buyer represents a loss for the option writer.

A fund that takes the position of a writer of a futures option is required to deposit and maintain initial and variation margin with respect to the option, as previously described in the case of futures contracts. A futures option transaction will not be considered to constitute the issuance, by a fund, of a "senior security," as that term is defined in Section 18(g) of the 1940 Act, and therefore such transaction will not be subject to the 300% asset coverage requirement otherwise applicable to borrowings by a fund, if the fund complies with Rule 18f-4.

Futures Contracts and Options on Futures Contracts-Risks. The risk of loss in trading futures contracts and in writing futures options can be substantial because of the low margin deposits required, the extremely high degree of leverage involved in futures and options pricing, and the potential high volatility of the futures markets. As a result, a relatively small price movement in a futures position may result in immediate and substantial loss (or gain) for the investor. For example, if at the time of purchase, 10% of the value of the futures contract is deposited as margin, a subsequent

10% decrease in the value of the futures contract would result in a total loss of the margin deposit, before any deduction for the transaction costs, if the account were then closed out. A 15% decrease would result in a loss equal to 150% of the original margin deposit if the contract were closed out. Thus, a purchase or sale of a futures contract, and the writing of a futures option, may result in losses in excess of the amount invested in the position. In the event of adverse price movements, a fund would continue to be required to make daily cash payments to maintain its required margin. In such situations, if the fund has insufficient cash, it may have to sell portfolio securities to meet daily margin requirements at a time when it may be disadvantageous to do so. In addition, on the settlement date, a fund may be required to make delivery of the instruments underlying the futures positions it holds.

A fund could suffer losses if it is unable to close out a futures contract or a futures option because of an illiquid secondary market. Futures contracts and futures options may be closed out only on an exchange that provides a secondary market for such products. However, there can be no assurance that a liquid secondary market will exist for any particular futures product at any specific time. Thus, it may not be possible to close a futures or option position. Moreover, most futures exchanges limit the amount of fluctuation permitted in futures contract prices during a single trading day. The daily limit establishes the maximum amount that the price of a futures contract may vary either up or down from the previous day's settlement price at the end of a trading session. Once the daily limit has been reached in a particular type of contract, no trades may be made on that day at a price beyond that limit. The daily limit governs only price movement during a particular trading day, and therefore does not limit potential losses because the limit may prevent the liquidation of unfavorable positions. Futures contract prices have occasionally moved to the daily limit for several consecutive trading days with little or no trading, thereby preventing prompt liquidation of future positions and subjecting some futures traders to substantial losses. The inability to close futures and options positions also could have an adverse impact on the ability to hedge a portfolio investment or to establish a substitute for a portfolio investment. U.S. Treasury futures are generally not subject to such daily limits.

A fund bears the risk that its advisor will incorrectly predict future market trends. If the advisor attempts to use a futures contract or a futures option as a hedge against, or as a substitute for, a portfolio investment, the fund will be exposed to the risk that the futures position will have or will develop imperfect or no correlation with the portfolio investment. This could cause substantial losses for the fund. Although hedging strategies involving futures products can reduce the risk of loss, they can also reduce the opportunity for gain or even result in losses by offsetting favorable price movements in other fund investments.

A fund could lose margin payments it has deposited with its FCM if, for example, the FCM breaches its agreement with the fund or becomes insolvent or goes into bankruptcy. In that event, the fund may be entitled to return of margin owed to it only in proportion to the amount received by the FCM's other customers, potentially resulting in losses to the fund.

Interfund Borrowing and Lending. The SEC has granted an exemption permitting registered open-end Vanguard funds to participate in Vanguard's interfund lending program. This program allows the Vanguard funds to borrow money from and lend money to each other for temporary or emergency purposes. The program is subject to a number of conditions, including, among other things, the requirements that (1) no fund may borrow or lend money through the program unless it receives a more favorable interest rate than is typically available from a bank for a comparable transaction, (2) no fund may lend money if the loan would cause its aggregate outstanding loans through the program to exceed 15% of its net assets at the time of the loan, and (3) a fund's interfund loans to any one fund shall not exceed

5% of the lending fund's net assets. In addition, a Vanguard fund may participate in the program only if and to the extent that such participation is consistent with the fund's investment objective and investment policies. The boards of trustees of the Vanguard funds are responsible for overseeing the interfund lending program. Any delay in repayment to a lending fund could result in a lost investment opportunity or additional borrowing costs.

Investing for Control. Each Vanguard fund invests in securities and other instruments for the sole purpose of achieving a specific investment objective. As such, a Vanguard fund does not seek to acquire, individually or collectively with any other Vanguard fund, enough of a company's outstanding voting stock to have control over management decisions. A Vanguard fund does not invest for the purpose of controlling a company's management.

Legal and Regulatory Risk. Vanguard funds and their advisors are subject to an extensive and complex set of laws and regulations. These laws and regulations have evolved rapidly in recent years and likely will continue to evolve. Changes and additions to laws and regulations can result in unintended or unexpected impacts, including impacts to the value of a fund's investments, a fund's investment strategy, and/or a fund's ability to manage tax consequences. In addition, complying with new or changing laws or regulations generally can be expected to increase operational costs, which can have a negative impact on fund performance.

Market Disruption. Significant market disruptions, such as those caused by pandemics, natural or environmental disasters, war, acts of terrorism, or other events, can adversely affect local and global markets and normal market operations. Market disruptions may exacerbate political, social, and economic risks discussed above and in a fund's prospectus. Additionally, market disruptions may result in increased market volatility; regulatory trading halts; closure of domestic or foreign exchanges, markets, or governments; or market participants operating pursuant to business continuity plans for indeterminate periods of time. Such events can be highly disruptive to economies and markets and significantly impact individual companies, sectors, industries, markets, currencies, interest and inflation rates, credit ratings, investor sentiment, and other factors affecting the value of a fund's investments and operation of a fund. These events could also result in the closure of businesses that are integral to a fund's operations or otherwise disrupt the ability of employees of fund service providers to perform essential tasks on behalf of a fund.

Options. An option is a derivative. An option on a security (or index) is a contract that gives the holder of the option, in return for the payment of a "premium," the right, but not the obligation, to buy from (in the case of a call option) or sell to (in the case of a put option) the writer of the option the security underlying the option (or the cash value of the index) at a specified exercise price prior to the expiration date of the option. The writer of an option on a security has the obligation upon exercise of the option to deliver the underlying security upon payment of the exercise price (in the case of a call option) or to pay the exercise price upon delivery of the underlying security (in the case of a put option). The writer of an option on an index has the obligation upon exercise of the option to pay an amount equal to the cash value of the index minus the exercise price, multiplied by the specified multiplier for the index option. The multiplier for an index option determines the size of the investment position the option represents. Unlike exchange-traded options, which are standardized with respect to the underlying instrument, expiration date, contract size, and strike price, the terms of over- the-counter (OTC) options (options not traded on exchanges) generally are established through negotiation with the other party to the option contract. Although this type of arrangement allows the purchaser or writer greater flexibility to tailor an option to its needs, OTC options generally involve credit risk to the counterparty, whereas for exchange-traded, centrally cleared options, credit risk is mutualized through the involvement of the applicable clearing house.

The buyer (or holder) of an option is said to be "long" the option, while the seller (or writer) of an option is said to be "short" the option. A call option grants to the holder the right to buy (and obligates the writer to sell) the underlying security at the strike price, which is the predetermined price at which the option may be exercised. A put option grants to the holder the right to sell (and obligates the writer to buy) the underlying security at the strike price. The purchase price of an option is called the "premium." The potential loss to an option buyer is limited to the amount of the premium plus transaction costs. This will be the case if the option is held and not exercised prior to its expiration date. Generally, an option writer sells options with the goal of obtaining the premium paid by the option buyer, but that person could also seek to profit from an anticipated rise or decline in option prices. If an option sold by an option writer expires without being exercised, the writer retains the full amount of the premium. The option writer, however, has unlimited economic risk because its potential loss, except to the extent offset by the premium received when the option was written, is equal to the amount the option is "in- the-money" at the expiration date. A call option is in-the-money if the value of the underlying position exceeds the exercise price of the option. A put option is in-the-money if the exercise price of the option exceeds the value of the underlying position. Generally, any profit realized by an option buyer represents a loss for the option writer. The writing of an option will not be considered to constitute the issuance, by a fund, of a "senior security," as that term is defined in Section 18(g) of the 1940 Act, and therefore such transaction will not be subject to the 300% asset coverage requirement otherwise applicable to borrowings by a fund, if the fund complies with Rule 18f-4.

If a trading market, in particular options, were to become unavailable, investors in those options (such as the funds) would be unable to close out their positions until trading resumes, and they may be faced with substantial losses if the value of the underlying instrument moves adversely during that time. Even if the market were to remain available, there may be times when options prices will not maintain their customary or anticipated relationships to the prices of the underlying instruments and related instruments. Lack of investor interest, changes in volatility, or other factors or conditions might adversely affect the liquidity, efficiency, continuity, or even the orderliness of the market for particular options.

A fund bears the risk that its advisor will not accurately predict future market trends. If the advisor attempts to use an option as a hedge against, or as a substitute for, a portfolio investment, the fund will be exposed to the risk that the option will have or will develop imperfect or no correlation with the portfolio investment, which could cause substantial losses for the fund. Although hedging strategies involving options can reduce the risk of loss, they can also reduce the opportunity for gain or even result in losses by offsetting favorable price movements in other fund investments. Many options, in particular OTC options, are complex and often valued based on subjective factors. Improper valuations can result in increased cash payment requirements to counterparties or a loss of value to a fund.

OTC Swap Agreements. An over-the-counter (OTC) swap agreement, which is a type of derivative, is an agreement between two parties (counterparties) to exchange payments at specified dates (periodic payment dates) on the basis of a specified amount (notional amount) with the payments calculated with reference to a specified asset, reference rate, or index.

Examples of OTC swap agreements include, but are not limited to, interest rate swaps, credit default swaps, equity swaps, commodity swaps, foreign currency swaps, index swaps, excess return swaps, and total return swaps. Most OTC swap agreements provide that when the periodic payment dates for both parties are the same, payments are netted and only the net amount is paid to the counterparty entitled to receive the net payment. Consequently, a fund's current obligations (or rights) under an OTC swap agreement will generally be equal only to the net amount to be paid or received under the agreement, based on the relative values of the positions held by each counterparty. OTC swap agreements allow for a wide variety of transactions. For example, fixed rate payments may be exchanged for floating rate payments; U.S. dollar-denominated payments may be exchanged for payments denominated in a different currency; and payments tied to the price of one asset, reference rate, or index may be exchanged for payments tied to the price of another asset, reference rate, or index.

An OTC option on an OTC swap agreement, also called a "swaption," is an option that gives the buyer the right, but not the obligation, to enter into a swap on a future date in exchange for paying a market-based "premium." A receiver swaption gives the owner the right to receive the total return of a specified asset, reference rate, or index. A payer swaption gives the owner the right to pay the total return of a specified asset, reference rate, or index. Swaptions also include options that allow an existing swap to be terminated or extended by one of the counterparties.

The use of OTC swap agreements by a fund entails certain risks, which may be different from, or possibly greater than, the risks associated with investing directly in the securities and other investments that are the referenced asset for the swap agreement. OTC swaps are highly specialized instruments that require investment techniques, risk analyses, and tax planning different from those associated with stocks, bonds, and other traditional investments. The use of an OTC swap requires an understanding not only of the referenced asset, reference rate, or index but also of the swap itself, without the benefit of observing the performance of the swap under all possible market conditions.

OTC swap agreements may be subject to liquidity risk, which exists when a particular swap is difficult to purchase or sell. If an OTC swap transaction is particularly large or if the relevant market is illiquid (as is the case with many OTC swaps), it may not be possible to initiate a transaction or liquidate a position at an advantageous time or price, which may result in significant losses. In addition, OTC swap transactions may be subject to a fund's limitation on investments in illiquid securities.

OTC swap agreements may be subject to pricing risk, which exists when a particular swap becomes extraordinarily expensive or inexpensive relative to historical prices or the prices of corresponding cash market instruments. Under certain market conditions, it may not be economically feasible to initiate a transaction or liquidate a position in time to avoid a loss or take advantage of an opportunity or to realize the intrinsic value of the OTC swap agreement.

Because certain OTC swap agreements have a leverage component, adverse changes in the value or level of the underlying asset, reference rate, or index can result in a loss substantially greater than the amount invested in the swap itself. Certain OTC swaps have the potential for unlimited loss, regardless of the size of the initial investment. A leveraged OTC swap transaction will not be considered to constitute the issuance, by a fund, of a "senior security," as that term is defined in Section 18(g) of the 1940 Act, and therefore such transaction will not be subject to the 300% asset coverage requirement otherwise applicable to borrowings by a fund, if the fund complies with Rule 18f-4.

Like most other investments, OTC swap agreements are subject to the risk that the market value of the instrument will change in a way detrimental to a fund's interest. A fund bears the risk that its advisor will not accurately forecast future market trends or the values of assets, reference rates, indexes, or other economic factors in establishing OTC swap positions for the fund. If the advisor attempts to use an OTC swap as a hedge against, or as a substitute for, a portfolio investment, the fund will be exposed to the risk that the OTC swap will have or will develop imperfect or no correlation with the portfolio investment. This could cause substantial losses for the fund. Although hedging strategies involving OTC swap instruments can reduce the risk of loss, they can also reduce the opportunity for gain or even result in losses by offsetting favorable price movements in other fund investments. Many OTC swaps are complex and often valued subjectively. Improper valuations can result in increased cash payment requirements to counterparties or a loss of value to a fund.

The use of an OTC swap agreement also involves the risk that a loss may be sustained as a result of the insolvency or bankruptcy of the counterparty or the failure of the counterparty to make required payments or otherwise comply with the terms of the agreement. Additionally, the use of credit default swaps can result in losses if a fund's advisor does not correctly evaluate the creditworthiness of the issuer on which the credit swap is based.

Ownership Limitations and Regulatory Relief. The ability of Vanguard and external advisors to purchase or dispose of certain fund investments, or to exercise rights on behalf of a fund, is or may be restricted or impaired because of limitations imposed by law, regulation, or by certain regulators or issuers. As a result, Vanguard and external advisors, on behalf of certain funds currently and other funds potentially in the future, are required to limit purchases, sell existing investments, or otherwise limit the exercise of shareholder rights by the fund, including voting rights. These ownership restrictions and limitations can impact a fund's performance. For index funds, this impact generally takes the form of tracking error, which can arise when a fund is not able to acquire its desired amount of a security. For actively managed funds, this impact can result, for example, in missed investment opportunities otherwise desired by a fund's investment advisor. If a fund is required to limit its investment in a particular issuer, then the fund may seek to obtain regulatory or corporate consents or ownership waivers. Other options a fund may pursue include seeking to obtain economic exposure to that issuer through alternative means, such as through a derivative or through investment in a totally held subsidiary, both of which may be more costly than owning securities of the issuer directly. In the event a derivative, such as a swap, is used as an alternative means of exposure, Vanguard and external advisors on behalf of a fund are not able to guarantee the availability of derivatives necessary to allow economic exposure to the security, sector, or industry. This limited availability may have additional impacts to fund performance. Additionally, use of derivatives as an alternative means of exposure subjects a fund to derivatives-related risks. Ownership restrictions and limitations could result in unanticipated tax consequences to the fund that may affect the amount, timing, and character of distributions to shareholders.

Other Investment Companies. A fund may invest in other investment companies, including ETFs, non-exchange traded U.S. registered open-end investment companies (mutual funds), and closed-end investment companies, to the extent permitted by applicable law or SEC exemption. Under Section 12(d)(1) of the 1940 Act, a fund may invest up to 10% of its assets in shares of investment companies generally and up to 5% of its assets in any one investment company, as long as no investment represents more than 3% of the voting stock of an acquired investment company. In addition, no funds for which Vanguard acts as an advisor may, in the aggregate, own more than 10% of the voting stock of a closed-end investment company.SEC Rule 12d1-4 under the 1940 Act permits registered investment companies to invest in other registered investment companies beyond the limits in Section 12(d)(1), subject to certain conditions, including that funds with different investment advisors must enter into a fund of funds investment agreement. Rule 12d1-4 is also designed to limit the use of complex fund structures. Under Rule 12d1-4, an acquired fund is prohibited from purchasing or otherwise acquiring the securities of another investment company or private fund if, immediately after the purchase, the securities of investment companies and private funds owned by the acquired fund have an aggregate value in excess of 10% of the value of the acquired fund's total assets, subject to certain limited exceptions. Accordingly, to the extent a fund's shares are sold to other investment companies in reliance on Rule 12d1-4, the acquired fund will be limited in the amount it could invest in other investment companies and private funds. If a fund invests in other investment companies, shareholders will bear not only their proportionate share of the fund's expenses (including operating expenses and the fees of the advisor), but they also may indirectly bear similar expenses of the underlying investment companies. Certain investment companies, such as business development companies (BDCs), are more akin to operating companies and, as such, their expenses are not direct expenses paid by fund shareholders and are not used to calculate the fund's net asset value. SEC rules nevertheless require that any expenses incurred by a BDC be included in a fund's expense ratio as "Acquired Fund Fees and Expenses." The expense ratio of a fund that holds a BDC will thus overstate what the fund actually spends on portfolio management, administrative services, and other shareholder services by an amount equal to these Acquired Fund Fees and Expenses. The Acquired Fund Fees and Expenses are not included in a fund's financial statements, which provide a

clearer picture of a fund's actual operating expenses. Shareholders would also be exposed to the risks associated not only with the investments of the fund but also with the portfolio investments of the underlying investment companies. Certain types of investment companies, such as closed-end investment companies, issue a fixed number of shares that typically trade on a stock exchange or over-the-counter at a premium or discount to their net asset value. Others are continuously offered at net asset value but also may be traded on the secondary market.

A fund may be limited to purchasing a particular share class of other investment companies (underlying funds). In certain cases, an investor may be able to purchase lower-cost shares of such underlying funds separately, and therefore be able to construct, and maintain over time, a similar portfolio of investments while incurring lower overall expenses.

Preferred Stock. Preferred stock represents an equity or ownership interest in an issuer. Preferred stock normally pays dividends at a specified rate and has precedence over common stock in the event the issuer is liquidated or declares bankruptcy. However, in the event an issuer is liquidated or declares bankruptcy, the claims of owners of bonds take precedence over the claims of those who own preferred and common stock. Preferred stock, unlike common stock, often has a stated dividend rate payable from the corporation's earnings. Preferred stock dividends may be cumulative or noncumulative, participating, or auction rate. "Cumulative" dividend provisions require all or a portion of prior unpaid dividends to be paid before dividends can be paid to the issuer's common stock. "Participating" preferred stock may be entitled to a dividend exceeding the stated dividend in certain cases. If interest rates rise, the fixed dividend on preferred stocks may be less attractive, causing the price of such stocks to decline. Preferred stock may have mandatory sinking fund provisions, as well as provisions allowing the stock to be called or redeemed, which can limit the benefit of a decline in interest rates. Preferred stock is subject to many of the risks to which common stock and debt securities are subject. In addition, preferred stock may be subject to more abrupt or erratic price movements than common stock or debt securities because preferred stock may trade with less frequency and in more limited volume.

Real Estate Investment Trusts (REITs). An equity REIT owns real estate properties directly and generates income from rental and lease payments. Equity REITs also have the potential to generate capital gains as properties are sold at a profit. A mortgage REIT makes construction, development, and long-term mortgage loans to commercial real estate developers and earns interest income on these loans. A hybrid REIT holds both properties and mortgages. To avoid taxation at the corporate level, REITs must distribute most of their earnings to shareholders.

Investments in REITs are subject to many of the same risks as direct investments in real estate. In general, real estate values can be affected by a variety of factors, including, but not limited to, supply and demand for properties, general or local economic conditions, and the strength of specific industries that rent properties. Ultimately, a REIT's performance depends on the types and locations of the properties it owns and on how well the REIT manages its properties. For example, rental income could decline because of extended vacancies, increased competition from nearby properties, tenants' failure to pay rent, regulatory limitations on rents, fluctuations in rental income, variations in market rental rates, or incompetent management. Property values could decrease because of overbuilding in the area, environmental liabilities, uninsured damages caused by natural disasters, a general decline in the neighborhood, losses because of casualty or condemnation, increases in property taxes, or changes in zoning laws.

The value of a REIT may also be affected by changes in interest rates. Rising interest rates generally increase the cost of financing for real estate projects, which could cause the value of an equity REIT to decline. During periods of declining interest rates, mortgagors may elect to prepay mortgages held by mortgage REITs, which could lower or diminish the yield on the REIT. REITs are also subject to heavy cash-flow dependency, default by borrowers, and changes in tax and regulatory requirements. In addition, a REIT may fail to meet the requirements for qualification and taxation as a REIT under the IRC and/or fail to maintain exemption from the 1940 Act.

Reliance on Service Providers, Data Providers, and Other Technology. Vanguard funds rely upon the performance of service providers to execute several key functions, which may include functions integral to a fund's operations. Failure by any service provider to carry out its obligations to a fund could disrupt the business of the fund and could have an adverse effect on the fund's performance. A fund's service providers' reliance on certain technology or information vendors (e.g., trading systems, investment analysis tools, benchmark analytics, and tax and accounting tools) could also adversely affect a fund and its shareholders. For example, a fund's investment advisor may use models and/or data with respect to potential investments for the fund. When models or data prove to be incorrect or incomplete, any decisions made in reliance upon such models or data expose a fund to potential risks.

Repurchase Agreements. A repurchase agreement is an agreement under which a fund acquires a debt security (generally a security issued by the U.S. government or an agency thereof, a banker's acceptance, or a certificate of deposit) from a bank, a broker, a dealer, or another counterparty that meets minimum credit requirements and

simultaneously agrees to resell such security to the seller at an agreed-upon price and date (normally, the next business day). Because the security purchased constitutes collateral for the repurchase obligation, a repurchase agreement may be considered a loan that is collateralized by the security purchased. The resale price reflects an agreed-upon interest rate effective for the period the instrument is held by a fund and is unrelated to the interest rate on the underlying instrument. In these transactions, the securities acquired by a fund (including accrued interest earned thereon) must have a total value in excess of the value of the repurchase agreement and be held by a custodian bank until repurchased. In addition, the investment advisor will monitor a fund's repurchase agreement transactions generally and will evaluate the creditworthiness of any bank, broker, dealer, or other counterparty that meets minimum credit requirements to a repurchase agreement relating to a fund. The aggregate amount of any such agreements is not limited, except to the extent required by law.

The use of repurchase agreements involves certain risks. One risk is the seller's ability to pay the agreed-upon repurchase price on the repurchase date. If the seller defaults, the fund may incur costs in disposing of the collateral, which would reduce the amount realized thereon. If the seller seeks relief under bankruptcy laws, the disposition of the collateral may be delayed or limited. For example, if the other party to the agreement becomes insolvent and subject to liquidation or reorganization under bankruptcy or other laws, a court may determine that the underlying security is collateral for a loan by the fund not within its control, and therefore the realization by the fund on such collateral may be automatically stayed. Finally, it is possible that the fund may not be able to substantiate its interest in the underlying security and may be deemed an unsecured creditor of the other party to the agreement.

Restricted and Illiquid Securities/Investments (including Private Placements). Illiquid securities/investments are investments that a fund reasonably expects cannot be sold or disposed of in current market conditions in seven calendar days or less without the sale or disposition significantly changing the market value of the investment. The SEC generally limits aggregate holdings of illiquid securities/investments by a mutual fund to 15% of its net assets (5% for money market funds). A fund may experience difficulty valuing and selling illiquid securities/investments and, in some cases, may be unable to value or sell certain illiquid securities for an indefinite period of time. Illiquid securities may include a wide variety of investments, such as (1) repurchase agreements maturing in more than seven days (unless the agreements have demand/redemption features), (2) OTC options contracts and certain other derivatives (including certain swap agreements), (3) fixed time deposits that are not subject to prepayment or do not provide for withdrawal penalties upon prepayment (other than overnight deposits), (4) certain loan interests and other direct debt instruments, (5) certain municipal lease obligations, (6) private equity investments, (7) commercial paper issued pursuant to Section 4(a)(2) of the 1933 Act, and (8) securities whose disposition is restricted under the federal securities laws. Illiquid securities/investments may include restricted, privately placed securities (such as private investments in public equity (PIPEs) or special purpose acquisition companies (SPACs)) that, under the federal securities laws, generally may be resold only to qualified institutional buyers. If a market develops for a restricted security held by a fund, it may be treated as a liquid security in accordance with guidelines approved by the board of trustees.

Reverse Repurchase Agreements. In a reverse repurchase agreement, a fund sells a security to another party, such as a bank or broker-dealer, in return for cash and agrees to repurchase that security at an agreed-upon price and time. Under a reverse repurchase agreement, the fund continues to receive any principal and interest payments on the underlying security during the term of the agreement. Reverse repurchase agreements involve the risk that the market value of securities retained by the fund may decline below the repurchase price of the securities sold by the fund that it is obligated to repurchase. In addition to the risk of such a loss, fees charged to the fund may exceed the return the fund earns from investing the proceeds received from the reverse repurchase agreement transaction. A reverse repurchase agreement may be considered a borrowing transaction for purposes of the 1940 Act. A reverse repurchase agreement transaction will not be considered to constitute the issuance, by a fund, of a "senior security," as that term is defined in Section 18(g) of the 1940 Act, and therefore such transaction will not be subject to the 300% asset coverage requirement otherwise applicable to borrowings by a fund, if the fund complies with Rule 18f-4. A fund will enter into reverse repurchase agreements only with parties whose creditworthiness has been reviewed and found satisfactory by the advisor. If the buyer in a reverse repurchase agreement becomes insolvent or files for bankruptcy, a fund's use of proceeds from the sale may be restricted while the other party or its trustee or receiver determines if it will honor the fund's right to repurchase the securities. If the fund is unable to recover the securities it sold in a reverse repurchase agreement, it would realize a loss equal to the difference between the value of the securities and the payment it received for them.

Securities Lending. A fund may lend its securities to financial institutions (typically brokers, dealers, and banks) to generate income for the fund. There are certain risks associated with lending securities, including counterparty, credit, market, regulatory, and operational risks. Vanguard considers the creditworthiness of the borrower, among other factors, in making decisions with respect to the lending of securities, subject to oversight by the board of trustees. If the

borrower defaults on its obligation to return the securities lent because of insolvency or other reasons, a fund could experience delays and costs in recovering the securities lent or in gaining access to the collateral. These delays and costs could be greater for certain types of foreign securities, as well as certain types of borrowers that are subject to global regulatory regimes. If a fund is not able to recover the securities lent, the fund may sell the collateral and purchase a replacement security in the market. Collateral investments are subject to market appreciation or depreciation. The value of the collateral could decrease below the value of the replacement investment by the time the replacement investment is purchased. Currently, a fund invests cash collateral into Vanguard Market Liquidity Fund, an affiliated money market fund that invests in high-quality, short-term money market instruments.

The terms and the structure of the loan arrangements, as well as the aggregate amount of securities loans, must be consistent with the 1940 Act and the rules or interpretations of the SEC thereunder. These provisions limit the amount of securities a fund may lend to 33 1⁄3% of the fund's total assets and require that (1) the borrower pledge and maintain with the fund collateral consisting of cash, an irrevocable letter of credit, or securities issued or guaranteed by the U.S. government having at all times not less than 100% of the value of the securities lent; (2) the borrower add to such collateral whenever the price of the securities lent rises (i.e., the borrower "marks to market" on a daily basis); (3) the loan be made subject to termination by the fund at any time; and (4) the fund receives reasonable interest on the loan (which may include the fund investing any cash collateral in interest-bearing short-term investments), any distribution on the lent securities, and any increase in their market value. Loan arrangements made by a fund will comply with any other applicable regulatory requirements. At the present time, the SEC does not object if an investment company pays reasonable negotiated fees in connection with lent securities, so long as such fees are set forth in a written contract and approved by the investment company's trustees. In addition, voting rights pass with the lent securities, but if a fund has knowledge that a material event will occur affecting securities on loan, and in respect to which the holder of the securities will be entitled to vote or consent, the lender must be entitled to call the loaned securities in time to vote or consent. A fund bears the risk that there may be a delay in the return of the securities, which may impair the fund's ability to vote on such a matter. See Tax Status of the Funds for information about certain tax consequences related to a fund's securities lending activities.

Pursuant to Vanguard's securities lending policy, Vanguard's fixed income and money market funds are not permitted to, and do not, lend their investment securities.

Tax Matters-Federal Tax Discussion. Discussion herein of U.S. federal income tax matters summarizes some of the important, generally applicable U.S. federal tax considerations relevant to investment in a fund based on the IRC, U.S. Treasury regulations, and other applicable authorities. These authorities are subject to change by legislative, administrative, or judicial action, possibly with retroactive effect. Each Fund has not requested and will not request an advance ruling from the Internal Revenue Service (IRS) as to the U.S. federal income tax matters discussed in this Statement of Additional Information. In some cases, a fund's tax position may be uncertain under current tax law and an adverse determination or future guidance by the IRS with respect to such a position could adversely affect the fund and its shareholders, including the fund's ability to continue to qualify as a regulated investment company or to continue to pursue its current investment strategy. A shareholder should consult his or her tax professional for information regarding the particular situation and the possible application of U.S. federal, state, local, foreign, and other taxes.

Tax Matters-Federal Tax Treatment of Derivatives, Hedging, and Related Transactions. A fund's transactions in derivative instruments (including, but not limited to, options, futures, forward contracts, and swap agreements), as well as any of the fund's hedging, short sale, securities loan, or similar transactions, may be subject to one or more special tax rules that accelerate income to the fund, defer losses to the fund, cause adjustments in the holding periods of the fund's securities, convert long-term capital gains into short-term capital gains, or convert short-term capital losses into long-term capital losses. These rules could therefore affect the amount, timing, and character of distributions to shareholders.

Because these and other tax rules applicable to these types of transactions are in some cases uncertain under current law, an adverse determination or future guidance by the IRS with respect to these rules (which determination or guidance could be retroactive) may affect whether a fund has made sufficient distributions, and otherwise satisfied the relevant requirements, to maintain its qualification as a regulated investment company and avoid a fund-level tax.

Tax Matters-Federal Tax Treatment of Futures Contracts. For federal income tax purposes, a fund generally must recognize, as of the end of each taxable year, any net unrealized gains and losses on certain futures contracts, as well as any gains and losses actually realized during the year. In these cases, any gain or loss recognized with respect to a futures contract is considered to be 60% long-term capital gain or loss and 40% short-term capital gain or loss, without regard to the holding period of the contract. Gains and losses on certain other futures contracts (primarily non-U.S. futures contracts) are not recognized until the contracts are closed and are treated as long-term or short-term,

depending on the holding period of the contract. Sales of futures contracts that are intended to hedge against a change in the value of securities held by a fund may affect the holding period of such securities and, consequently, the nature of the gain or loss on such securities upon disposition. A fund may be required to defer the recognition of losses on one position, such as futures contracts, to the extent of any unrecognized gains on a related offsetting position held by the fund.

A fund will distribute to shareholders annually any net capital gains that have been recognized for federal income tax purposes on futures transactions. Such distributions will be combined with distributions of capital gains realized on the fund's other investments, and shareholders will be advised on the nature of the distributions.

Tax Matters-Federal Tax Treatment of Non-U.S. Currency Transactions. Special rules generally govern the federal income tax treatment of a fund's transactions in the following: non-U.S. currencies; non-U.S. currency-denominated debt obligations; and certain non-U.S. currency options, futures contracts, forward contracts, and similar instruments.

Accordingly, if a fund engages in these types of transactions it may have ordinary income or loss to the extent that such income or loss results from fluctuations in the value of the non-U.S. currency concerned. Such ordinary income could accelerate fund distributions to shareholders and increase the distributions taxed to shareholders as ordinary income. Any ordinary loss so created will generally reduce ordinary income distributions and, in some cases, could require the recharacterization of prior ordinary income distributions. Net ordinary losses cannot be carried forward by the fund to offset income or gains realized in subsequent taxable years.

Any gain or loss attributable to the non-U.S. currency component of a transaction engaged in by a fund that is not subject to these special currency rules (such as foreign equity investments other than certain preferred stocks) will generally be treated as a capital gain or loss and will not be segregated from the gain or loss on the underlying transaction.

To the extent a fund engages in non-U.S. currency hedging, the fund may elect or be required to apply other rules that could affect the character, timing, or amount of the fund's gains and losses. For more information, see "Tax Matters- Federal Tax Treatment of Derivatives, Hedging, and Related Transactions."

Tax Matters-Foreign Tax Credit. Foreign governments may withhold taxes on dividends and interest paid with respect to foreign securities held by a fund. Foreign governments may also impose taxes on other payments or gains with respect to foreign securities. If, at the close of its fiscal year, more than 50% of a fund's total assets are invested in securities of foreign issuers, the fund may elect to pass through to shareholders the ability to deduct or, if they meet certain holding period requirements, take a credit for foreign taxes paid by the fund. Similarly, if at the close of each quarter of a fund's taxable year, at least 50% of its total assets consist of interests in other regulated investment companies, the fund is permitted to elect to pass through to its shareholders the foreign income taxes paid by the fund in connection with foreign securities held directly by the fund or held by a regulated investment company in which the fund invests that has elected to pass through such taxes to shareholders.

Tax Matters-Passive Foreign Investment Companies. To the extent that a fund invests in stock in a foreign company, such stock may constitute an equity investment in a passive foreign investment company (PFIC). A foreign company is generally a PFIC if 75% or more of its gross income is passive or if 50% or more of its assets produce passive income. Capital gains on the sale of an interest in a PFIC will be deemed ordinary income regardless of how long a fund held it. Also, a fund may be subject to corporate income tax and an interest charge on certain dividends and capital gains earned in respect to PFIC interests, whether or not such amounts are distributed to shareholders. To avoid such tax and interest, a fund may elect to "mark to market" its PFIC interests, that is, to treat such interests as sold on the last day of a fund's fiscal year, and to recognize any unrealized gains (or losses, to the extent of previously recognized gains) as ordinary income (or loss) each year. Distributions from a fund that are attributable to income or gains earned in respect to PFIC interests are characterized as ordinary income.

Tax Matters-Market Discount or Premium. The price of a bond purchased after its original issuance may reflect market discount or premium. Depending on the particular circumstances, market discount may affect the tax character and amount of income required to be recognized by a fund holding the bond. In determining whether a bond is purchased with market discount, certain de minimis rules apply. Premium is generally amortizable over the remaining term of the bond. Depending on the type of bond, premium may affect the amount of income required to be recognized by a fund holding the bond and the fund's basis in the bond.

Tax Matters-Real Estate Mortgage Investment Conduits. If a fund invests directly or indirectly, including through a REIT or other pass-through entity, in residual interests in real estate mortgage investment conduits (REMICs) or equity interests in taxable mortgage pools (TMPs), a portion of the fund's income that is attributable to a residual interest in a REMIC or an equity interest in a TMP (such portion referred to in the IRC as an "excess inclusion") will be subject to U.S. federal income tax in all events-including potentially at the fund level-under a notice issued by the IRS in October 2006 and U.S. Treasury regulations that have yet to be issued but may apply retroactively. This notice also provides, and the regulations are expected to provide, that excess inclusion income of a regulated investment company will be allocated to shareholders of the regulated investment company in proportion to the dividends received by such shareholders, with the same consequences as if the shareholders held the related interest directly. In general, excess inclusion income allocated to shareholders (1) cannot be offset by net operating losses (subject to a limited exception for certain thrift institutions); (2)

Vanguard Internal Use Only

will constitute unrelated business taxable income (UBTI) to entities (including a qualified pension plan, an individual retirement account, a 401(k) plan, a Keogh plan, or other tax-exempt entity) subject to tax on UBTI, thereby potentially requiring such an entity, which otherwise might not be required, to file a tax return and pay tax on such income; and (3) in the case of a non-U.S. investor, will not qualify for any reduction in U.S. federal withholding tax. A shareholder will be subject to U.S. federal income tax on such inclusions notwithstanding any exemption from such income tax otherwise available under the IRC. As a result, a fund investing in such interests may not be suitable for charitable remainder trusts.

See "Tax Matters-Tax-Exempt Investors."

Tax Matters-Tax Considerations for Non-U.S. Investors. U.S. withholding and estate taxes and certain U.S. tax reporting requirements may apply to any investments made by non-U.S. investors in Vanguard funds. Certain properly reported distributions of qualifying interest income or short-term capital gain made by a fund to its non-U.S. investors are exempt from U.S. withholding taxes, provided the investors furnish valid tax documentation (i.e., IRS Form W-8) certifying as to their non-U.S. status.

A fund is permitted, but is not required, to report any of its distributions as eligible for such relief, and some distributions (e.g., distributions of interest a fund receives from non-U.S. issuers) are not eligible for this relief. For some funds, Vanguard has chosen to report qualifying distributions and apply the withholding exemption to those distributions when made to non-U.S. shareholders who invest directly with Vanguard. For other funds, Vanguard may choose not to apply the withholding exemption to qualifying fund distributions made to direct shareholders, but may provide the reporting to such shareholders. In these cases, a shareholder may be able to reclaim such withholding tax directly from the IRS.

If shareholders hold fund shares (including ETF shares) through a broker or intermediary, their broker or intermediary may apply this relief to properly reported qualifying distributions made to shareholders with respect to those shares. If a shareholder's broker or intermediary instead collects withholding tax where the fund has provided the proper reporting, the shareholder may be able to reclaim such withholding tax from the IRS. Please consult your broker or intermediary regarding the application of these rules.

This relief does not apply to any withholding required under the Foreign Account Tax Compliance Act (FATCA), which generally requires a fund to obtain information sufficient to identify the status of each of its shareholders. If a shareholder fails to provide this information or otherwise fails to comply with FATCA, a fund may be required to withhold under FATCA at a rate of 30% with respect to that shareholder on fund distributions. Please consult your tax advisor for more information about these rules.

Tax Matters-Tax-Exempt Investors. Income of a fund that would be UBTI if earned directly by a tax-exempt entity will not generally be attributed as UBTI to a tax-exempt shareholder of the fund. Notwithstanding this "blocking" effect, a tax- exempt shareholder could realize UBTI by virtue of its investment in a fund if shares in the fund constitute debt-financed property in the hands of the tax-exempt shareholder within the meaning of IRC Section 514(b).

A tax-exempt shareholder may also recognize UBTI if a fund recognizes "excess inclusion income" derived from direct or indirect investments in residual interests in REMICs or equity interests in TMPs. See "Tax Matters-Real Estate Mortgage

Investment Conduits."

In addition, special tax consequences apply to charitable remainder trusts that invest in a fund that invests directly or indirectly in residual interests in REMICs or equity interests in TMPs. Charitable remainder trusts and other tax-exempt investors are urged to consult their tax advisors concerning the consequences of investing in a fund.

Time Deposits. Time deposits are subject to the same risks that pertain to domestic issuers of money market instruments, most notably credit risk (and, to a lesser extent, income risk, market risk, and liquidity risk). Additionally, time deposits of foreign branches of U.S. banks and foreign branches of foreign banks may be subject to certain sovereign risks. One such risk is the possibility that a sovereign country might prevent capital, in the form of U.S. dollars, from flowing across its borders. Other risks include adverse political and economic developments, the extent and quality of government regulation of financial markets and institutions, the imposition of foreign withholding taxes, and expropriation or nationalization of foreign issuers. However, time deposits of such issuers will undergo the same type of credit analysis as domestic issuers in which a Vanguard fund invests and will have at least the same financial strength as the domestic issuers approved for the fund.

Warrants. Warrants are instruments that give the holder the right, but not the obligation, to buy an equity security at a specific price for a specific period of time. Changes in the value of a warrant do not necessarily correspond to changes in the value of its underlying security. The price of a warrant may be more volatile than the price of its underlying security, and a warrant may offer greater potential for capital appreciation as well as capital loss. Warrants do not entitle a holder to dividends or voting rights with respect to the underlying security and do not represent any rights in the assets

of the issuing company. A warrant ceases to have value if it is not exercised prior to its expiration date. These factors can make warrants more speculative than other types of investments. Other kinds of warrants exist, including, but not limited to, warrants linked to countries' economic performance or to commodity prices such as oil prices. These warrants may be subject to risk from fluctuation of underlying assets or indexes, as well as credit risk that the issuer does not pay on the obligations and risk that the data used for warrant payment calculation does not accurately reflect the true underlying commodity price or economic performance.

When-Issued, Delayed-Delivery, and Forward-Commitment Transactions. When-issued, delayed-delivery, and forward-commitment transactions involve a commitment to purchase or sell specific securities at a predetermined price or yield in which payment and delivery take place after the customary settlement period for that type of security. Typically, no interest accrues to the purchaser until the security is delivered. When purchasing securities pursuant to one of these transactions, payment for the securities is not required until the delivery date. However, the purchaser assumes the rights and risks of ownership, including the risks of price and yield fluctuations and the risk that the security will not be issued as anticipated. When a fund has sold a security pursuant to one of these transactions, the fund does not participate in further gains or losses with respect to the security. If the other party to a delayed-delivery transaction fails to deliver or pay for the securities, the fund could miss a favorable price or yield opportunity or suffer a loss. A fund may renegotiate a when- issued or forward-commitment transaction and may sell the underlying securities before delivery, which may result in capital gains or losses for the fund. When-issued, delayed-delivery, and forward-commitment transactions will not be considered to constitute the issuance, by a fund, of a "senior security," as that term is defined in Section 18(g) of the 1940 Act, and therefore such transaction will not be subject to the 300% asset coverage requirement otherwise applicable to borrowings by the fund, if the fund complies with Rule 18f-4.

SHARE PRICE

Each Fund's share price, also known as net asset value (NAV), is typically calculated as of the close of regular trading on the New York Stock Exchange (NYSE), generally 4 p.m., Eastern time, on each day that the NYSE is open for business (a business day). In the rare event the NYSE experiences unanticipated disruptions and is unavailable at the close of the trading day, each Fund reserves the right to treat such day as a business day and calculate NAVs as of the close of regular trading on the Nasdaq (or another alternate exchange if the Nasdaq is unavailable, as determined at Vanguard's discretion), generally 4 p.m., Eastern time. The NAV per share is computed by dividing the total assets, minus liabilities, of the Fund by the number of Fund shares outstanding. On U.S. holidays or other days when the NYSE is closed, the NAV is not calculated, and the Funds do not sell or redeem shares.

The NYSE typically observes the following holidays: New Year's Day; Martin Luther King, Jr., Day; Presidents' Day (Washington's Birthday); Good Friday; Memorial Day; Juneteenth National Independence Day; Independence Day; Labor Day; Thanksgiving Day; and Christmas Day. Although each Fund expects the same holidays to be observed in the future, the NYSE may modify its holiday schedule or hours of operation at any time.

PURCHASE AND REDEMPTION OF SHARES

Purchase of Shares

The purchase price of shares of each Fund is the NAV per share next determined after the purchase request is received in good order, as defined in the Fund's prospectus.

Each Fund reserves the right at its sole discretion to impose a purchase fee if the purchase, in the opinion of the advisor, would disrupt the efficient management of the Fund. Lump-sum purchases may be considered disruptive, for example, if the advisor incurs significant transaction costs in purchasing securities needed to match the investment performance of the respective benchmark index. If such purchases can be offset by redemptions of shares by other shareholders, such fee may be waived or reduced. A prospective investor may determine whether a fee will be charged by calling their client representative or plan sponsor in advance of a purchase.

Exchange of Securities for Shares of a Fund. Shares of a Fund may be purchased "in kind" (i.e., in exchange for securities, rather than for cash) at the discretion of the Fund's portfolio manager. Such securities must not be restricted as to transfer and must have a value that is readily ascertainable. Securities accepted by the Fund will be valued, as set forth in the Fund's prospectus, as of the time of the next determination of NAV after such acceptance. All dividend,

subscription, or other rights that are reflected in the market price of accepted securities at the time of valuation become the property of the Fund and must be delivered to the Fund by the investor upon receipt from the issuer. A gain or loss for federal income tax purposes, depending upon the cost of the securities tendered, would be realized by the investor upon the exchange. Investors interested in purchasing fund shares in kind should contact Vanguard.

Redemption of Shares

The redemption price of shares of each Fund is the NAV per share next determined after the redemption request is received in good order, as defined in the Fund's prospectus.

Each Fund can postpone payment of redemption proceeds for up to seven calendar days. In addition, each Fund can suspend redemptions and/or postpone payments of redemption proceeds beyond seven calendar days (1) during any period that the NYSE is closed or trading on the NYSE is restricted as determined by the SEC; (2) during any period when an emergency exists, as defined by the SEC, as a result of which it is not reasonably practicable for the Fund to dispose of securities it owns or to fairly determine the value of its assets; or (3) for such other periods as the SEC may permit.

The Trust has filed a notice of election with the SEC to pay in cash all redemptions requested by any shareholder of record limited in amount during any 90-day period to the lesser of $250,000 or 1% of the net assets of a Fund at the beginning of such period.

If Vanguard determines that it would be detrimental to the best interests of the remaining shareholders of a Fund to make payment wholly or partly in cash, the Fund may pay the redemption price in whole or in part by a distribution in kind of readily marketable securities held by the Fund in lieu of cash in conformity with applicable rules of the SEC and in accordance with procedures adopted by the Fund's board of trustees. Investors may incur brokerage charges on the sale of such securities received in payment of redemptions.

The Funds do not charge redemption fees. Shares redeemed may be worth more or less than what was paid for them, depending on the market value of the securities held by the Funds.

Vanguard processes purchase and redemption requests through a pooled account. Pending investment direction or distribution of redemption proceeds, the assets in the pooled account are invested and any earnings (the "float") are allocated proportionately among the Vanguard funds in order to offset fund expenses. Other than the float, Vanguard treats assets held in the pooled account as the assets of each shareholder making such purchase or redemption request.

Right to Change Policies

Vanguard reserves the right, without notice, to (1) alter, add, or discontinue any conditions of purchase (including eligibility requirements), redemption, exchange, conversion, service, or privilege at any time and (2) alter, impose, discontinue, or waive any purchase fee, redemption fee, account service fee, or other fee charged to a shareholder or a group of shareholders. Changes may affect any or all investors. These actions will be taken when, at the sole discretion of Vanguard management, Vanguard believes they are in the best interest of a fund.

Account Restrictions

Vanguard reserves the right to: (1) redeem all or a portion of a fund/account to meet a legal obligation, including tax withholding, tax lien, garnishment order, or other obligation imposed on your account by a court or government agency;

(2)redeem shares, close an account, or suspend account privileges, features, or options in the case of threatening conduct or activity; (3) redeem shares, close an account, or suspend account privileges, features, or options if Vanguard believes or suspects that not doing so could result in a suspicious, fraudulent, or illegal transaction; (4) place restrictions on the ability to redeem any or all shares in an account if it is required to do so by a court or government agency; (5) place restrictions on the ability to redeem any or all shares in an account if Vanguard believes that doing so will prevent fraud or financial exploitation or abuse, or will protect vulnerable investors; (6) freeze any account and/or suspend account services if Vanguard has received reasonable notice of a dispute regarding the assets in an account, including notice of a dispute between the registered or beneficial account owners; and (7) freeze any account and/or suspend account services upon initial notification to Vanguard of the death of an account owner.

Investing With Vanguard Through Other Firms

Each Fund has authorized certain agents to accept on its behalf purchase and redemption orders, and those agents are authorized to designate other intermediaries to accept purchase and redemption orders on the Fund's behalf (collectively, Authorized Agents). A Fund will be deemed to have received a purchase or redemption order when an Authorized Agent accepts the order in accordance with the Fund's instructions. In most instances, a customer order that is properly transmitted to an Authorized Agent will be priced at the NAV per share next determined after the order is received by the Authorized Agent.

MANAGEMENT OF THE FUNDS

Vanguard

Each Fund is part of the Vanguard group of investment companies, which consists of over 200 funds. Each fund is a series of a Delaware statutory trust. The funds obtain virtually all of their corporate management, administrative, and distribution services through the trusts' jointly owned subsidiary, Vanguard. Vanguard may contract with certain third-party service providers to assist Vanguard in providing certain administrative and/or accounting services with respect to the funds, subject to Vanguard's oversight. Vanguard also provides investment advisory services to certain Vanguard funds. All of these services are provided at Vanguard's total cost of operations pursuant to the Fifth Amended and Restated Funds' Service Agreement (the Agreement).

Vanguard employs a supporting staff of management and administrative personnel needed to provide the requisite services to the funds and also furnishes the funds with necessary office space, furnishings, and equipment. Each fund (other than a fund of funds) pays its share of Vanguard's total expenses, which are allocated among the funds under methods approved by the board of trustees of each fund. In addition, each fund bears its own direct expenses, such as legal, auditing, and custodial fees.

The funds' officers are also employees of Vanguard.

Vanguard, Vanguard Marketing Corporation (VMC), the funds, and the funds' advisors have adopted codes of ethics designed to prevent employees who may have access to nonpublic information about the trading activities of the funds (access persons) from profiting from that information. The codes of ethics permit access persons to invest in securities for their own accounts, including securities that may be held by a fund, but place substantive and procedural restrictions on the trading activities of access persons. For example, the codes of ethics require that access persons receive advance approval for most securities trades to ensure that there is no conflict with the trading activities of the funds.

Vanguard was established and operates under the Agreement. The Agreement provides that each Vanguard fund may be called upon to invest up to 0.40% of its net assets in Vanguard. The amounts that each fund has invested are adjusted from time to time in order to maintain the proportionate relationship between each fund's relative net assets and its contribution to Vanguard's capital.

As of the date of this SAI, Vanguard 0-3 Month Treasury Bill ETF and Vanguard Ultra-Short Treasury ETF had not commenced operations and therefore had not contributed capital to Vanguard.

Management. Corporate management and administrative services include (1) executive staff, (2) accounting and financial, (3) legal and regulatory, (4) shareholder account maintenance, (5) monitoring and control of custodian relationships, (6) shareholder reporting, and (7) review and evaluation of advisory and other services provided to the funds by third parties.

Distribution. Vanguard Marketing Corporation, 100 Vanguard Boulevard, Malvern, PA 19355, a wholly owned subsidiary of Vanguard, is the principal underwriter for the funds and in that capacity performs and finances marketing, promotional, and distribution activities (collectively, marketing and distribution activities) that are primarily intended to result in the sale of the funds' shares. VMC offers shares of each fund for sale on a continuous basis and will use all reasonable efforts in connection with the distribution of shares of the funds. VMC performs marketing and distribution activities in accordance with the conditions of a 1981 SEC exemptive order that permits the Vanguard funds to internalize and jointly finance the marketing, promotion, and distribution of their shares. The funds' trustees review and approve the marketing and distribution expenses incurred by the funds, including the nature and cost of the activities and the desirability of each fund's continued participation in the joint arrangement.

To ensure that each fund's participation in the joint arrangement falls within a reasonable range of fairness, each fund contributes to VMC's marketing and distribution expenses in accordance with an SEC-approved formula. Under that formula, one half of the marketing and distribution expenses are allocated among the funds based upon their relative net assets. The remaining half of those expenses is allocated among the funds based upon each fund's sales for the preceding 24 months relative to the total sales of the funds as a group, provided, however, that no fund's aggregate quarterly rate of contribution for marketing and distribution expenses shall exceed 125% of the average marketing and distribution expense rate for Vanguard and that no fund shall incur annual marketing and distribution expenses in excess of 0.20% of its average month-end net assets. Each fund's contribution to these marketing and distribution expenses helps to maintain and enhance the attractiveness and viability of the Vanguard complex as a whole, which benefits all of the funds and their shareholders.

VMC's principal marketing and distribution expenses are for advertising, promotional materials, and marketing personnel. Other marketing and distribution activities of an administrative nature that VMC undertakes on behalf of the funds may include, but are not limited to:

■Conducting or publishing Vanguard-generated research and analysis concerning the funds, other investments, the financial markets, or the economy.

■Providing views, opinions, advice, or commentary concerning the funds, other investments, the financial markets, or the economy.

■Providing analytical, statistical, performance, or other information concerning the funds, other investments, the financial markets, or the economy.

■Providing administrative services in connection with investments in the funds or other investments, including, but not limited to, shareholder services, recordkeeping services, and educational services.

■Providing products or services that assist investors or financial service providers (as defined below) in the investment decision-making process.

VMC performs most marketing and distribution activities itself. Some activities may be conducted by third parties pursuant to shared marketing arrangements under which VMC agrees to share the costs and performance of marketing and distribution activities in concert with a financial service provider. Financial service providers include, but are not limited to, investment advisors, broker-dealers, financial planners, financial consultants, banks, and insurance companies. Under these cost- and performance-sharing arrangements, VMC may pay or reimburse a financial service provider (or a third party it retains) for marketing and distribution activities that VMC would otherwise perform. VMC's cost- and performance- sharing arrangements may be established in connection with Vanguard investment products or services offered or provided to or through the financial service providers.

VMC's arrangements for shared marketing and distribution activities may vary among financial service providers, and its payments or reimbursements to financial service providers in connection with shared marketing and distribution activities may be significant. VMC, as a matter of policy, does not pay asset-based fees, sales-based fees, or account-based fees to financial service providers in connection with its marketing and distribution activities for the Vanguard funds. VMC does make fixed dollar payments to financial service providers when sponsoring, jointly sponsoring, financially supporting, or participating in conferences, programs, seminars, presentations, meetings, or other events involving fund shareholders, financial service providers, or others concerning the funds, other investments, the financial markets, or the economy, such as industry conferences, prospecting trips, due diligence visits, training or education meetings, and sales presentations. VMC also makes fixed dollar payments to financial service providers for data regarding funds, such as statistical information regarding sales of fund shares. In addition, VMC makes fixed dollar payments for expenses associated with financial service providers' use of Vanguard's funds including, but not limited to, the use of funds in model portfolios. These payments may be used for services including, but not limited to, technology support and development; platform support and development; due diligence related to products used on a platform; legal, regulatory, and compliance expenses related to a platform; and other platform-related services.

In connection with its marketing and distribution activities, VMC may give financial service providers (or their representatives) (1) promotional items of nominal value that display Vanguard's logo, such as golf balls, shirts, towels, pens, and mouse pads; (2) gifts that do not exceed $100 per person annually and are not preconditioned on achievement of a sales target; (3) an occasional meal, a ticket to a sporting event or the theater, or comparable entertainment that is neither so frequent nor so extensive as to raise any question of propriety and is not preconditioned on achievement of a sales target; and (4) reasonable travel and lodging accommodations to facilitate participation in marketing and distribution activities.

VMC policy prohibits marketing and distribution activities that are intended, designed, or likely to compromise suitability determinations by, or the fulfillment of any fiduciary duties or other obligations that apply to, financial service providers. Nonetheless, VMC's marketing and distribution activities are primarily intended to result in the sale of the funds' shares, and as such, its activities, including shared marketing and distribution activities and fixed dollar payments as described above, may influence applicable financial service providers (or their representatives) to recommend, promote, include, or invest in a Vanguard fund or share class. In addition, Vanguard or any of its subsidiaries may retain a financial service provider to provide consulting or other services, and that financial service provider also may provide services to investors. Investors should consider the possibility that any of these activities, relationships, or payments may influence a financial service provider's (or its representatives') decision to recommend, promote, include, or invest in a Vanguard fund or share class. Each financial service provider should consider its suitability determinations, fiduciary duties, and other legal obligations (or those of its representatives) in connection with any decision to consider, recommend, promote, include, or invest in a Vanguard fund or share class.

As of the date of this SAI, Vanguard 0-3 Month Treasury Bill ETF and Vanguard Ultra-Short Treasury ETF had not commenced operations and therefore had not incurred any annual shared fund operating expenses.

Officers and Trustees

Each Vanguard fund is governed by the board of trustees of its trust and a single set of officers. Consistent with the board's corporate governance principles, the trustees believe that their primary responsibility is oversight of the management of each fund for the benefit of its shareholders, not day-to-day management. The trustees set broad policies for the funds; select investment advisors; monitor fund operations, regulatory compliance, performance, and costs; nominate and select new trustees; and elect fund officers. Vanguard manages the day-to-day operations of the funds under the direction of the board of trustees.

The trustees play an active role, as a full board and at the committee level, in overseeing risk management for the funds. The trustees delegate the day-to-day risk management of the funds to various groups, including portfolio review, investment management, risk management, compliance, legal, fund accounting, and fund services and oversight. These groups provide the trustees with regular reports regarding investment, valuation, liquidity, and compliance, as well as the risks associated with each. The trustees also oversee risk management for the funds through regular interactions with the funds' internal and external auditors.

The full board participates in the funds' risk oversight, in part, through the Vanguard funds' compliance program, which covers the following broad areas of compliance: investment and other operations; recordkeeping; valuation and pricing; communications and disclosure; reporting and accounting; oversight of service providers; fund governance; and codes of

ethics, insider trading controls, and protection of nonpublic information. The program seeks to identify and assess risk through various methods, including through regular interdisciplinary communications between compliance professionals and business personnel who participate on a daily basis in risk management on behalf of the funds. The funds' chief compliance officer regularly provides reports to the board in writing and in person.

The audit committee of the board, which is composed of F. Joseph Loughrey, Mark Loughridge, Sarah Bloom Raskin, and Peter F. Volanakis, each of whom is an independent trustee, oversees management of financial risks and controls. The audit committee serves as the channel of communication between the independent auditors of the funds and the board with respect to financial statements and financial reporting processes, systems of internal control, and the audit process. Vanguard's head of internal audit reports directly to the audit committee and provides reports to the committee in writing and in person on a regular basis. Although the audit committee is responsible for overseeing the management of financial risks, the entire board is regularly informed of these risks through committee reports.

All of the trustees bring to each fund's board a wealth of executive leadership experience derived from their service as executives (in many cases chief executive officers), board members, and leaders of diverse public operating companies, academic institutions, and other organizations. In determining whether an individual is qualified to serve as a trustee of the funds, the board considers a wide variety of information about the trustee, and multiple factors contribute to the board's decision. Each trustee is determined to have the experience, skills, and attributes necessary to serve the funds and their shareholders because each trustee demonstrates an exceptional ability to consider complex business and financial matters, evaluate the relative importance and priority of issues, make decisions, and contribute effectively to the deliberations of the board. The board also considers the individual experience of each trustee and determines that the trustee's professional experience, education, and background contribute to the diversity of perspectives on the board. The business acumen, experience, and objective thinking of the trustees are considered invaluable assets for Vanguard management and, ultimately, the Vanguard funds' shareholders. The specific roles and experience of each board member that factor into this determination are presented on the following pages. The mailing address of the trustees and officers is P.O. Box 876, Valley Forge, PA 19482.

The trustees designate an independent chair of the board. The independent chair is a spokesperson and principal point of contact for the trustees and is responsible for coordinating the activities of the trustees, including calling regular executive sessions of the trustees; developing the agenda of each meeting together with the chief executive officer; and chairing the meetings of the trustees. The independent chair also chairs the meetings of the audit, compensation, nominating, and independent governance committees.

Board Committees: The Trust's board has the following committees:

■Audit Committee: This committee oversees the accounting and financial reporting policies, the systems of internal controls, and the independent audits of each fund. The following independent trustees serve as members of the committee: Mr. Loughrey, Mr. Loughridge, Ms. Raskin, and Mr. Volanakis.

■Compensation Committee: This committee oversees the compensation programs established by each fund for the

benefit of its trustees. The following independent trustees serve as members of the committee: Ms. Bunch, Mr. Loughrey, Mr. Loughridge, Mr. Malpass, and Mr. Reid.

■Independent Governance Committee: This committee assists the board in fulfilling its responsibilities and is empowered to exercise board powers in the intervals between board meetings unless such action is prohibited by applicable law or Trust bylaws. The following independent trustees serve as members of the committee: Mr. Loughridge, Mr. Perold, Ms. Raskin, and Mr. Volanakis.

■Investment Committees: These committees assist the board in its oversight of investment advisors to the funds and in the review and evaluation of materials relating to the board's consideration of investment advisory agreements with the funds. Each trustee serves on one of two investment committees.

■Nominating Committee: This committee nominates candidates for election to the board of trustees of each fund. The committee also has the authority to recommend the removal of any trustee. The following independent trustees serve as members of the committee: Ms. Bunch, Mr. Fullwood, Mr. Loughridge, Mr. Malpass, and Dr. Thomas.

equivalent investments, derivatives, and other investment positions (collectively, other investment positions) held by the fund.

Online Disclosure of Complete Portfolio Holdings

Each actively managed Vanguard fund, unless otherwise stated, generally will seek to disclose the fund's complete portfolio holdings as of the end of the most recent calendar quarter online at vanguard.com 30 calendar days after the end of the calendar quarter. In accordance with Rule 2a-7 under the 1940 Act, each of the Vanguard money market funds will disclose the fund's complete portfolio holdings as of the last business day of the prior month online at vanguard.com no later than the fifth business day of the current month. The complete portfolio holdings information for money market funds will remain available online for at least six months after the initial posting. Each Vanguard index fund, other than those Vanguard index funds relying on Rule 6c-11 under the 1940 Act (e.g., standalone ETFs), generally will seek to disclose the fund's complete portfolio holdings as of the end of the most recent month online at vanguard.com, 15 calendar days after the end of the month. Online disclosure of complete portfolio holdings is made to all categories of persons, including individual investors, institutional investors, intermediaries, third-party service providers, rating and ranking organizations, affiliated persons of a Vanguard fund, and all other persons. Vanguard will review complete portfolio holdings before disclosure is made and, except with respect to the complete portfolio holdings of the Vanguard money market funds, may withhold any portion of the fund's complete portfolio holdings from disclosure when deemed to be in the best interests of the fund after consultation with a Vanguard fund's investment advisor.

Disclosure of Complete Portfolio Holdings to Service Providers Subject to Confidentiality and Trading Restrictions

Vanguard, for legitimate business purposes, may disclose Vanguard fund complete portfolio holdings at times it deems necessary and appropriate to rating and ranking organizations; financial printers; proxy voting service providers; pricing information vendors; issuers of guaranteed investment contracts for stable value portfolios; third parties that deliver analytical, statistical, or consulting services; and other third parties that provide services (collectively, Service Providers) to Vanguard, Vanguard subsidiaries, and/or the Vanguard funds. Disclosure of complete portfolio holdings to a Service Provider is conditioned on the Service Provider being subject to a written agreement imposing a duty of confidentiality, including a duty not to trade on the basis of any material nonpublic information.

The frequency with which complete portfolio holdings may be disclosed to a Service Provider, and the length of the lag, if any, between the date of the information and the date on which the information is disclosed to the Service Provider, is determined based on the facts and circumstances, including, without limitation, the nature of the portfolio holdings information to be disclosed, the risk of harm to the funds and their shareholders, and the legitimate business purposes served by such disclosure. The frequency of disclosure to a Service Provider varies and may be as frequent as daily, with no lag. Disclosure of Vanguard fund complete portfolio holdings by Vanguard to a Service Provider must be authorized by a Vanguard fund officer or a Principal in Vanguard's Portfolio Review Department or Office of the General Counsel. Any disclosure of Vanguard fund complete portfolio holdings to a Service Provider as previously described may also include a list of the other investment positions that make up the fund, such as cash equivalent investments and derivatives.

Currently, Vanguard fund complete portfolio holdings are disclosed to the following Service Providers as part of ongoing arrangements that serve legitimate business purposes: Abel/Noser Corporation; Advisor Software, Inc.; Alcom Printing Group Inc.; Apple Press, L.C.; Bloomberg L.P.; Brilliant Graphics, Inc.; Broadridge Financial Solutions, Inc.; Brown Brothers Harriman & Co.; Canon Business Process Services; Charles River Systems, Inc.; Eagle Investments; Equilend; FactSet Research Systems Inc.; Gresham Technologies, Plc.; Innovation Printing & Communications; Institutional Shareholder Services, Inc.; Intelligencer Printing Company; Investment Technology Group, Inc.; Lipper, Inc.; Markit WSO Corporation; McMunn Associates, Inc.; Morningstar; Pirium; Reuters America Inc.; R.R. Donnelley, Inc.; State Street Bank and Trust Company; Stonewain; and Trade Informatics LLC.

Disclosure of Complete Portfolio Holdings to Vanguard Affiliates and Certain Fiduciaries Subject to Confidentiality and Trading Restrictions

Vanguard fund complete portfolio holdings may be disclosed between and among the following persons (collectively, Affiliates and Fiduciaries) for legitimate business purposes within the scope of their official duties and responsibilities, subject to such persons' continuing legal duty of confidentiality and legal duty not to trade on the basis of any material nonpublic information, as such duties are imposed under the Code of Ethical Conduct, the Policies and Procedures Designed to Prevent the Misuse of Inside Information, by agreement, or under applicable laws, rules, and regulations: (1) persons who are subject to the Code of Ethical Conduct or the Policies and Procedures Designed to Prevent the Misuse of Inside Information; (2) an investment advisor, sub-advisor, distributor, administrator, transfer agent, or custodian to a Vanguard fund; (3) an accounting firm, an auditing firm, or outside legal counsel retained by Vanguard, a Vanguard subsidiary, or a Vanguard fund; (4) an investment advisor to whom complete portfolio holdings are disclosed for due diligence purposes when the advisor is in merger or acquisition talks with a Vanguard fund's current advisor; and (5) a newly hired investment advisor or sub-advisor to whom complete portfolio holdings are disclosed prior to the time it commences its duties.

The frequency with which complete portfolio holdings may be disclosed between and among Affiliates and Fiduciaries, and the length of the lag, if any, between the date of the information and the date on which the information is disclosed between and among the Affiliates and Fiduciaries, is determined by such Affiliates and Fiduciaries based on the facts and circumstances, including, without limitation, the nature of the portfolio holdings information to be disclosed, the risk of harm to the funds and their shareholders, and the legitimate business purposes served by such disclosure. The frequency of disclosure between and among Affiliates and Fiduciaries varies and may be as frequent as daily, with no lag. Any disclosure of Vanguard fund complete portfolio holdings to any Affiliates and Fiduciaries as previously described may also include a list of the other investment positions that make up the fund, such as cash equivalent investments and derivatives. Disclosure of Vanguard fund complete portfolio holdings or other investment positions by Vanguard, VMC, or a Vanguard fund to Affiliates and Fiduciaries must be authorized by a Vanguard fund officer or a Principal of Vanguard.

Currently, Vanguard discloses complete portfolio holdings to the following Affiliates and Fiduciaries as part of ongoing arrangements that serve legitimate business purposes: Vanguard and each investment advisor, sub-advisor, custodian, and independent registered public accounting firm identified in each fund's Statement of Additional Information.

Disclosure of Portfolio Holdings to Trading Counterparties in the Normal Course of Managing a Fund's Assets

An investment advisor, sub-advisor, administrator, or custodian for a Vanguard fund may, for legitimate business purposes within the scope of its official duties and responsibilities, disclose portfolio holdings (whether partial portfolio holdings or complete portfolio holdings) and other investment positions that make up the fund to any trading counterparty, including one or more broker-dealers or banks, during the course of, or in connection with, normal day-to-day securities and derivatives transactions with or through such trading counterparties subject to the counterparty's legal obligation not to use or disclose material nonpublic information concerning the fund's portfolio holdings, other investment positions, securities transactions, or derivatives transactions without the consent of the fund or its agents. The Vanguard funds have not given their consent to any such use or disclosure and no person or agent of Vanguard is authorized to give such consent except as approved in writing by the Boards of the Vanguard funds. Disclosure of portfolio holdings or other investment positions by Vanguard to trading counterparties must be authorized by a Vanguard fund officer or a Principal of Vanguard.

In addition to the disclosures described below to Authorized Participants, a Vanguard fund investment advisor or administrator may also disclose portfolio holdings information to other current or prospective fund shareholders in connection with the dissemination of information necessary for transactions in Creation Units (as defined below) or other large transactions with a Vanguard fund. Such shareholders are typically Authorized Participants or other financial institutions that have been authorized by VMC to purchase and redeem large blocks of shares, but may also include market makers and other institutional market participants and entities to whom a Vanguard fund advisor or administrator may provide information in connection with transactions in a Vanguard fund.

Disclosure of Nonmaterial Information

The Policies and Procedures permit Vanguard fund officers, Vanguard fund portfolio managers, and other Vanguard representatives (collectively, Approved Vanguard Representatives) to disclose any views, opinions, judgments, advice, or commentary, or any analytical, statistical, performance, or other information, in connection with or relating to a Vanguard fund or its portfolio holdings and/or other investment positions (collectively, commentary and analysis) or any changes in the portfolio holdings of a Vanguard fund that occurred after the end of the most recent calendar quarter (recent portfolio changes) to any person if (1) such disclosure serves a legitimate business purpose, (2) such disclosure does not effectively result in the disclosure of the complete portfolio holdings of any Vanguard fund (which can be disclosed only in accordance with the Policies and Procedures), and (3) such information does not constitute material nonpublic information. Disclosure of commentary and analysis or recent portfolio changes by Vanguard, VMC, or a Vanguard fund must be authorized by a Vanguard fund officer or a Principal of Vanguard.

An Approved Vanguard Representative must make a good faith determination whether the information constitutes material nonpublic information, which involves an assessment of the particular facts and circumstances. Vanguard believes that in most cases recent portfolio changes that involve a few or even several securities in a diversified portfolio or commentary and analysis would be immaterial and would not convey any advantage to a recipient in making an investment decision concerning a Vanguard fund. Nonexclusive examples of commentary and analysis about a Vanguard fund include (1) the allocation of the fund's portfolio holdings and other investment positions among various asset classes, sectors, industries, and countries; (2) the characteristics of the stock and bond components of the fund's

portfolio holdings and other investment positions; (3) the attribution of fund returns by asset class, sector, industry, and country; and (4) the volatility characteristics of the fund. Approved Vanguard Representatives may, at their sole discretion, deny any request for information made by any person, and may do so for any reason or for no reason. Approved Vanguard Representatives include, for purposes of the Policies and Procedures, persons employed by or associated with Vanguard or a subsidiary of Vanguard who have been authorized by Vanguard's Portfolio Review Department to disclose recent portfolio changes and/or commentary and analysis in accordance with the Policies and Procedures.

Disclosure of Portfolio Holdings, Including Other Investment Positions, in Accordance with Securities and Exchange Commission (SEC) Exemptive Orders and Rule 6c-11

Vanguard's Fund Services and Oversight unit may disclose to the National Securities Clearing Corporation (NSCC), Authorized Participants, and other market makers the daily portfolio composition files (PCFs) that identify a basket of specified securities that may overlap with the actual or expected portfolio holdings of the Vanguard funds that offer a class of shares known as Vanguard ETF Shares (ETF Funds). Each Vanguard fund relying on Rule 6c-11 under the 1940 Act generally will seek to disclose complete portfolio holdings, including other investment positions, at the beginning of each business day. These portfolio holdings, including other investment positions, will be disclosed online at vanguard.com. The disclosure of PCFs and portfolio holdings, including other investment positions, will be in accordance with the terms and conditions of related exemptive orders (Vanguard ETF Exemptive Orders) issued by the SEC or Rule 6c-11 under the 1940 Act, as described in this section. In addition to disclosing PCFs to the NSCC, as previously described, Vanguard's Fund Services and Oversight unit will generally disclose the PCF for any ETF Fund online at vanguard.com.

Unlike the conventional classes of shares issued by ETF Funds, the ETF Shares are listed for trading on a national securities exchange. Each ETF Fund issues and redeems ETF Shares in large blocks, known as "Creation Units." To purchase or redeem a Creation Unit, an investor must be an "Authorized Participant" or the investor must purchase or redeem through a broker-dealer that is an Authorized Participant. An Authorized Participant is a participant in the Depository Trust Company (DTC) that has executed a "Participant Agreement" with VMC. Each ETF Fund issues Creation Units in exchange for a "portfolio deposit" consisting of a basket of specified securities (Deposit Securities) and a cash payment (Balancing Amount). Each ETF Fund also generally redeems Creation Units in kind; an investor who tenders a Creation Unit will receive, as redemption proceeds, a basket of specified securities together with a Balancing Amount.

In connection with the creation and redemption process, and in accordance with the terms and conditions of the Vanguard ETF Exemptive Orders and Rule 6c-11, Vanguard makes available to the NSCC (a clearing agency registered with the SEC and affiliated with the DTC), for dissemination to NSCC participants on each business day prior to the opening of trading on the listing exchange, a PCF containing a list of the names and the required number of shares of each Deposit Security for each ETF Fund. In addition, the listing exchange disseminates (1) continuously throughout the trading day, through the facilities of the Consolidated Tape Association, the market value of an ETF Share; and (2) every 15 seconds throughout the trading day, a calculation of the estimated NAV of an ETF Share (expected to be accurate to within a few basis points). Comparing these two figures allows an investor to determine whether, and to what extent, ETF Shares are selling at a premium or at a discount to NAV. ETF Shares are listed on the exchange and traded on the secondary market in the same manner as other equity securities. The price of ETF Shares trading on the secondary market is based on a current bid/offer market.

Disclosure of Portfolio Holdings Related Information to the Issuer of a Security for Legitimate Business Purposes

Vanguard, at its sole discretion, may disclose portfolio holdings information concerning a security held by one or more Vanguard funds to the issuer of such security if the issuer presents, to the satisfaction of Vanguard's Fund Services and Oversight unit, convincing evidence that the issuer has a legitimate business purpose for such information. Disclosure of this information to an issuer is conditioned on the issuer being subject to a written agreement imposing a duty of confidentiality, including a duty not to trade on the basis of any material nonpublic information. The frequency with which portfolio holdings information concerning a security may be disclosed to the issuer of such security, and the length of the lag, if any, between the date of the information and the date on which the information is disclosed to the issuer, is determined based on the facts and circumstances, including, without limitation, the nature of the portfolio holdings information to be disclosed, the risk of harm to the funds and their shareholders, and the legitimate business purposes served by such disclosure. The frequency of disclosure to an issuer cannot be determined in advance of a specific request and will vary based upon the particular facts and circumstances and the legitimate business purposes, but in unusual situations could be as frequent as daily, with no lag. Disclosure of portfolio holdings information concerning a security held by one or more Vanguard funds to the issuer of such security must be authorized by a Vanguard fund officer or a Principal in Vanguard's Equity Investment Group, Portfolio Review Department, or Office of the General Counsel.

Disclosure of Portfolio Holdings as Required by Applicable Law

Vanguard fund portfolio holdings (whether partial portfolio holdings or complete portfolio holdings) and other investment positions that make up a fund shall be disclosed to any person as required by applicable laws, rules, and regulations. Examples of such required disclosure include, but are not limited to, disclosure of Vanguard fund portfolio holdings (1) in a filing or submission with the SEC or another regulatory body, (2) in connection with seeking recovery on defaulted bonds in a federal bankruptcy case, (3) in connection with a lawsuit, or (4) as required by court order. Disclosure of portfolio holdings or other investment positions by Vanguard, VMC, or a Vanguard fund as required by applicable laws, rules, and regulations must be authorized by a Vanguard fund officer or a Principal of Vanguard.

Prohibitions on Disclosure of Portfolio Holdings

No person is authorized to disclose Vanguard fund portfolio holdings or other investment positions (whether online at vanguard.com, in writing, by fax, by email, orally, or by other means) except in accordance with the Policies and Procedures. In addition, no person is authorized to make disclosure pursuant to the Policies and Procedures if such disclosure is otherwise unlawful under the antifraud provisions of the federal securities laws (as defined in Rule 38a-1 under the 1940 Act). Furthermore, Vanguard's management, at its sole discretion, may determine not to disclose portfolio holdings or other investment positions that make up a Vanguard fund to any person who would otherwise be eligible to receive such information under the Policies and Procedures, or may determine to make such disclosures publicly as provided by the Policies and Procedures.

Prohibitions on Receipt of Compensation or Other Consideration

The Policies and Procedures prohibit a Vanguard fund, its investment advisor, and any other person or entity from paying or receiving any compensation or other consideration of any type for the purpose of obtaining disclosure of Vanguard fund portfolio holdings or other investment positions. "Consideration" includes any agreement to maintain assets in the fund or in other investment companies or accounts managed by the investment advisor or sub-advisor or by any affiliated person of the investment advisor or sub-advisor.

INVESTMENT ADVISORY AND OTHER SERVICES

The Funds receive all investment advisory services from Vanguard, through its Equity Index Group. These services are provided by an experienced advisory staff employed directly by Vanguard. The compensation and other expenses of the advisory staff are allocated among the funds utilizing these services.

As of the date of this SAI, Vanguard Ultra-Short Treasury ETF and Vanguard 0-3 Month Treasury Bill ETF had not commenced operations and therefore had not incurred any advisory expenses.

1. Other Accounts Managed

The following table provides information relating to the other accounts managed by the portfolio managers of the Funds as of the fiscal year ended December 31, 202x (unless otherwise noted):

2. Material Conflicts of Interest

At Vanguard, individual portfolio managers may manage multiple accounts for multiple clients. In addition to mutual funds, these accounts may include separate accounts, collective trusts, and offshore funds. Managing multiple funds or accounts may give rise to potential conflicts of interest including, for example, conflicts among investment strategies and conflicts in the allocation of investment opportunities. Vanguard manages potential conflicts between funds or accounts through allocation policies and procedures, internal review processes, and oversight by trustees and independent third parties. Vanguard has developed trade allocation procedures and controls to ensure that no one client, regardless of type, is intentionally favored at the expense of another. Allocation policies are designed to address potential conflicts in situations in which two or more funds or accounts participate in investment decisions involving the same securities.

3. Description of Compensation

All Vanguard portfolio managers are Vanguard employees. This section describes the compensation of the Vanguard employees who manage Vanguard mutual funds. As of xx, a Vanguard portfolio manager's compensation generally consists of base salary, bonus, and payments under Vanguard's long-term incentive compensation program. In addition, portfolio managers are eligible for the standard retirement benefits and health and welfare benefits available to all Vanguard employees. Also, certain portfolio managers may be eligible for additional retirement benefits under several supplemental retirement plans that Vanguard adopted in the 1980s to restore dollar-for-dollar the benefits of management employees that had been cut back solely as a result of tax law changes. These plans are structured to provide the same retirement benefits as the standard retirement plans.

In the case of portfolio managers responsible for managing multiple Vanguard funds or accounts, the method used to determine their compensation is the same for all funds and investment accounts. A portfolio manager's base salary is determined by the manager's experience and performance in the role, taking into account the ongoing compensation benchmark analyses performed by Vanguard's Human Resources Department. A portfolio manager's base salary is generally a fixed amount that may change as a result of an annual review, upon assumption of new duties, or when a market adjustment of the position occurs.

A portfolio manager's bonus is determined by a number of factors. One factor is gross, pre-tax performance of the fund relative to expectations for how the fund should have performed, given the fund's investment objective, policies, strategies, and limitations, and the market environment during the measurement period. This performance factor is not based on the amount of assets held in any individual fund's portfolio. For each Fund, the performance factor depends on how closely the portfolio manager tracks the Fund's benchmark index over a one-year period. Additional factors include the portfolio manager's contributions to the investment management functions within the sub-asset class, contributions to the development of other investment professionals and supporting staff, and overall contributions to strategic planning and decisions for the investment group. The target bonus is expressed as a percentage of base salary. The actual bonus paid may be more or less than the target bonus, based on how well the manager satisfies the objectives previously described. The bonus is paid on an annual basis.

Under the long-term incentive compensation program, all full-time employees receive a payment from Vanguard's long- term incentive compensation plan based on their years of service, job level, and if applicable, management responsibilities. Each year, Vanguard's independent directors determine the amount of the long-term incentive compensation award for that year based on the investment performance of the Vanguard funds relative to competitors and Vanguard's operating efficiencies in providing services to the Vanguard funds.

4. Ownership of Securities

As of the date of this SAI, Vanguard Ultra-Short Treasury ETF and Vanguard 0-3 Month Treasury Bill ETF had not commenced operations, and therefore the portfolio manager did not own any shares of the Funds.

Duration and Termination of Investment Advisory Agreement

Vanguard provides investment advisory services to the Funds pursuant to the terms of the Fifth Amended and Restated Funds' Service Agreement. This agreement will continue in full force and effect until terminated or amended by mutual agreement of the Vanguard funds and Vanguard.

PORTFOLIO TRANSACTIONS

The advisor decides which securities to buy and sell on behalf of a Fund and then selects the brokers or dealers that will execute the trades on an agency basis or the dealers with whom the trades will be effected on a principal basis. For each trade, the advisor must select a broker-dealer that it believes will provide "best execution." Best execution does not necessarily mean paying the lowest spread or commission rate available. In seeking best execution, the SEC has said that an advisor should consider the full range of a broker-dealer's services. The factors considered by the advisor in seeking best execution include, but are not limited to, the broker-dealer's execution capability, clearance and settlement services, commission rate, trading expertise, willingness and ability to commit capital, ability to provide anonymity, financial responsibility, reputation and integrity, responsiveness, access to underwritten offerings and secondary markets, and access to company management, as well as the value of any research provided by the broker-dealer. In assessing which broker-dealer can provide best execution for a particular trade, the advisor also may consider the timing and size of the order and available liquidity and current market conditions. Subject to applicable legal requirements, the advisor may select a broker based partly on brokerage or research services provided to the advisor and its clients, including the Funds. The advisor may cause the Fund to pay a higher commission than other brokers would charge if the advisor determines in good faith that the amount of the commission is reasonable in relation to the value of services provided. The advisor also may receive brokerage or research services from broker-dealers that are provided at no charge in recognition of the volume of trades directed to the broker. To the extent research services or products may be a factor in selecting brokers, services and products may include written research reports analyzing performance or securities, discussions with research analysts, meetings with corporate executives to obtain oral reports on company performance, market data, and other products and services that will assist the advisor in its investment decision-making process. The research services provided by brokers through which a Fund effects securities transactions may be used by the advisor in servicing all of its accounts, and some of the services may not be used by the advisor in connection with the Fund.

As of the date of this SAI, Vanguard Ultra-Short Treasury ETF and Vanguard 0-3 Month Treasury Bill ETF had not commenced operations and therefore had not incurred any brokerage commissions.

Some securities that are considered for investment by a Fund may also be appropriate for other Vanguard funds or for other clients served by the advisor. If such securities are compatible with the investment policies of a Fund and one or more of an advisor's other clients, and are considered for purchase or sale at or about the same time, then transactions in such securities may be aggregated by the advisor, and the purchased securities or sale proceeds may be allocated among the participating Vanguard funds and the other participating clients of the advisor in a manner deemed equitable by the advisor. Although there may be no specified formula for allocating such transactions, the allocation methods used, and the results of such allocations, will be subject to periodic review by the Funds' board of trustees.

As of the date of this SAI, Vanguard Ultra-Short Treasury ETF and Vanguard 0-3 Month Treasury Bill ETF had not commenced operations and therefore had not held securities of its "regular brokers or dealers," as that term is defined in Rule 10b-1 of the 1940 Act.

PROXY VOTING

I. Proxy Voting Policies

Each Vanguard fund advised by Vanguard retains the authority to vote proxies received with respect to the shares of equity securities held in a portfolio advised by Vanguard. The Board of Trustees of the Vanguard-advised funds (the Board) has adopted proxy voting procedures and guidelines to govern proxy voting for each portfolio retaining proxy voting authority, which are summarized in Appendix A.

Vanguard has entered into agreements with various state, federal, and non-U.S. regulators and with certain issuers that limit the amount of shares that the funds may vote at their discretion for particular securities. For these securities, the funds are able to vote a limited portion of the shares at their discretion. Any additional shares generally are voted in the

of its participants (DTC Participants) and to facilitate the clearance and settlement of transactions among them through electronic book-entry changes in their accounts, thereby eliminating the need for physical movement of securities certificates. DTC Participants include securities brokers and dealers, banks, trust companies, clearing corporations, and certain other organizations. The DTC is a subsidiary of the Depository Trust and Clearing Corporation (DTCC), which is owned by certain participants of the DTCC's subsidiaries, including the DTC. Access to the DTC system is also available to others such as banks, brokers, dealers, and trust companies that clear through or maintain a custodial relationship with a DTC Participant, either directly or indirectly (Indirect Participants).

Beneficial ownership of ETF Shares is limited to DTC Participants, Indirect Participants, and persons holding interests through DTC Participants and Indirect Participants. Ownership of beneficial interests in ETF Shares (owners of such beneficial interests are referred to herein as Beneficial Owners) is shown on, and the transfer of ownership is effected only through, records maintained by the DTC (with respect to DTC Participants) and on the records of DTC Participants (with respect to Indirect Participants and Beneficial Owners that are not DTC Participants). Beneficial Owners will receive from, or through, the DTC Participant a written confirmation relating to their purchase of ETF Shares. The laws of some jurisdictions may require that certain purchasers of securities take physical delivery of such securities. Such laws may impair the ability of certain investors to acquire beneficial interests in ETF Shares.

Each ETF Fund recognizes the DTC or its nominee as the record owner of all ETF Shares for all purposes. Beneficial Owners of ETF Shares are not entitled to have ETF Shares registered in their names and will not receive or be entitled to physical delivery of share certificates. Each Beneficial Owner must rely on the procedures of the DTC and any DTC Participant and/or Indirect Participant through which such Beneficial Owner holds its interests to exercise any rights of a holder of ETF Shares.

Conveyance of all notices, statements, and other communications to Beneficial Owners is effected as follows. The DTC will make available to each ETF Fund, upon request and for a fee, a listing of the ETF Shares of the Fund held by each DTC Participant. The ETF Fund shall obtain from each DTC Participant the number of Beneficial Owners holding ETF Shares, directly or indirectly, through the DTC Participant. The ETF Fund shall provide each DTC Participant with copies of such notice, statement, or other communication, in form, in number, and at such place as the DTC Participant may reasonably request, in order that these communications may be transmitted by the DTC Participant, directly or indirectly, to the Beneficial Owners. In addition, the ETF Fund shall pay to each DTC Participant a fair and reasonable amount as reimbursement for the expenses attendant to such transmittal, subject to applicable statutory and regulatory requirements.

Share distributions shall be made to the DTC or its nominee as the registered holder of all ETF Shares. The DTC or its nominee, upon receipt of any such distributions, shall immediately credit the DTC Participants' accounts with payments in amounts proportionate to their respective beneficial interests in ETF Shares of the appropriate ETF Fund as shown on the records of the DTC or its nominee. Payments by DTC Participants to Indirect Participants and Beneficial Owners of ETF Shares held through such DTC Participants will be governed by standing instructions and customary practices, as is now the case with securities held for the accounts of customers in bearer form or registered in a "street name," and will be the responsibility of such DTC Participants.

The ETF Funds have no responsibility or liability for any aspects of the records relating to or notices to Beneficial Owners; for payments made on account of beneficial ownership interests in such ETF Shares; for maintenance, supervision, or review of any records relating to such beneficial ownership interests; or for any other aspect of the relationship between the DTC and DTC Participants or the relationship between such DTC Participants and the Indirect Participants and Beneficial Owners owning through such DTC Participants.

The DTC may determine to discontinue providing its service with respect to ETF Shares at any time by giving reasonable notice to the ETF Funds and discharging its responsibilities with respect thereto under applicable law. Under such circumstances, the ETF Funds shall take action either to find a replacement for the DTC to perform its functions at a comparable cost or, if such replacement is unavailable, to issue and deliver printed certificates representing ownership of ETF Shares, unless the ETF Funds make other arrangements with respect thereto satisfactory to the exchange.

Purchase and Issuance of ETF Shares in Creation Units

The ETF Funds issue and sell ETF Shares only in Creation Units on a continuous basis through the Distributor, without a sales load, at their NAV next determined after receipt of an order in proper form on any business day. The ETF Funds do not issue fractional Creation Units.

A business day is any day on which the NYSE is open for business. As of the date of this Statement of Additional Information, the NYSE observes the following U.S. holidays: New Year's Day; Martin Luther King, Jr., Day; Presidents' Day (Washington's Birthday); Good Friday; Memorial Day; Juneteenth National Independence Day; Independence Day; Labor Day; Thanksgiving Day; and Christmas Day.

Fund Deposit. The consideration for purchase of a Creation Unit from an ETF Fund generally consists of an in-kind deposit of a designated portfolio of securities (Deposit Securities) and an amount of cash (Cash Component) consisting of a purchase balancing amount and a transaction fee (both described in the following paragraphs). Together, the Deposit Securities and the Cash Component constitute the fund deposit.

The purchase balancing amount is an amount equal to the difference between the NAV of a Creation Unit and the market value of the Deposit Securities (Deposit Amount). It ensures that the NAV of a fund deposit (not including the transaction fee) is identical to the NAV of the Creation Unit it is used to purchase. If the purchase balancing amount is a positive number (i.e., the NAV per Creation Unit exceeds the market value of the Deposit Securities), then that amount will be paid by the purchaser to an ETF Fund in cash. If the purchase balancing amount is a negative number (i.e., the NAV per Creation Unit is less than the market value of the Deposit Securities), then that amount will be paid by an ETF Fund to the purchaser in cash (except as offset by the transaction fee).

Vanguard, through the National Securities Clearing Corporation (NSCC), makes available after the close of each business day a list of the names and the number of shares of each Deposit Security to be included in the next business day's fund deposit for each ETF Fund (subject to possible amendment or correction). Each ETF Fund reserves the right to accept a nonconforming fund deposit.

The identity and number of shares of the Deposit Securities required for a fund deposit may change from one day to another to reflect rebalancing adjustments, corporate actions, and interest payments on underlying bonds or to respond to adjustments to the weighting or composition of the component securities of the relevant target index.

In addition, each ETF Fund reserves the right to permit or require the substitution of an amount of cash-referred to as "cash in lieu"-to be added to the Cash Component to replace any Deposit Security. This might occur, for example, if a Deposit Security is not available in sufficient quantity for delivery, is not eligible for transfer through the applicable clearance and settlement system, or is not eligible for trading by an Authorized Participant or the investor for which an Authorized Participant is acting. Trading costs incurred by the ETF Fund in connection with the purchase of Deposit Securities with cash-in-lieu amounts will be an expense of the ETF Fund. However, Vanguard may adjust the transaction fee to protect existing shareholders from this expense.

All questions as to the number of shares of each security in the Deposit Securities and the validity, form, eligibility, and acceptance for deposit of any securities to be delivered shall be determined by the appropriate Fund, and the Fund's determination shall be final and binding.

Procedures for Purchasing Creation Units. To initiate a purchase order for a Creation Unit, an Authorized Participant must submit an order in proper form to the Distributor and such order must be received by the Distributor prior to the closing time of regular trading of the NYSE (Closing Time) (ordinarily 4 p.m., Eastern time) to receive that day's NAV. Authorized Participants must transmit orders using a transmission method acceptable to the Distributor pursuant to procedures set forth in the Participant Agreement.

Neither the Trust, the ETF Funds, the Distributor, nor any affiliated party will be liable to an investor who is unable to submit a purchase order by Closing Time, even if the problem is the responsibility of one of those parties (e.g., the Distributor's phone or email systems were not operating properly).

If you are not an Authorized Participant, you must place your purchase order in an acceptable form with an Authorized Participant. The Authorized Participant may request that you make certain representations or enter into agreements with respect to the order (e.g., to provide for payments of cash when required).

ETF Shares may be redeemed only in Creation Units. Investors should expect to incur brokerage and other transaction costs in connection with assembling a sufficient number of ETF Shares to constitute a redeemable Creation Unit. There can be no assurance, however, that there will be sufficient liquidity in the public trading market at any time to permit assembly of a Creation Unit. Redemption requests received on a business day in good order will receive the NAV next determined after the request is made.

Unless cash redemptions are available or specified for an ETF Fund, an investor tendering a Creation Unit generally will receive redemption proceeds consisting of (1) a basket of Redemption Securities; plus (2) a redemption balancing amount in cash equal to the difference between (x) the NAV of the Creation Unit being redeemed, as next determined after receipt of a request in proper form, and (y) the value of the Redemption Securities; less (3) a transaction fee. If the Redemption Securities have a value greater than the NAV of a Creation Unit, the redeeming investor will pay the redemption balancing amount in cash to the ETF Fund, rather than receive such amount from the Fund.

Vanguard, through the NSCC, makes available after the close of each business day a list of the names and the number of shares of each Redemption Security to be included in the next business day's redemption basket for each ETF Fund (subject to possible amendment or correction). The basket of Redemption Securities provided to an investor redeeming a Creation Unit may not be identical to the basket of Deposit Securities required of an investor purchasing a Creation Unit. An ETF Fund may provide a redeeming investor with a basket of Redemption Securities that differs from the composition of the redemption basket published through the NSCC.

Each ETF Fund reserves the right to deliver cash in lieu of any Redemption Security for the same reason it might accept cash in lieu of a Deposit Security, as previously discussed, or if the ETF Fund could not lawfully deliver the security or could not do so without first registering such security under federal or state law.

Neither the Trust, the ETF Funds, the Distributor, nor any affiliated party will be liable to an investor who is unable to submit a redemption order by Closing Time, even if the problem is the responsibility of one of those parties (e.g., the Distributor's phone or email systems were not operating properly).

Transaction Fee on Redemptions of Creation Units. Each ETF Fund may impose a transaction fee (payable to the Fund) to compensate the ETF Fund for costs associated with the redemption of Creation Units. The amount of the fee, which may be changed by each ETF Fund from time to time at its sole discretion, is made available daily to Authorized Participants, market makers, and other interested parties through Vanguard's proprietary portal system. An additional charge may be imposed for redemptions of Creation Units effected outside the Clearing Process. When an ETF Fund permits (or requires) a redeeming investor to receive cash in lieu of one or more Redemption Securities, the ETF Fund may assess an additional variable charge on the cash portion of the redemption. The amount will vary as determined by the ETF Fund at its sole discretion and is made available daily to Authorized Participants, market makers, and other interested parties through Vanguard's proprietary portal system. The maximum transaction fee, including any variable charges, on redemptions of Creation Units shall be 2% of the value of the Creation Units.

Each ETF Fund reserves the right to not impose a transaction fee or to vary the amount of the transaction fee imposed, up to the maximum amount listed above. To the extent a redemption transaction fee is not charged or does not cover the costs associated with the redemption of the Creation Units, certain costs may be borne by the Fund.

Placement of Redemption Orders. To initiate a redemption order for a Creation Unit, an Authorized Participant must submit such order in proper form to the Distributor before Closing Time in order to receive that day's NAV. Authorized Participants must transmit orders using a transmission method acceptable to the Distributor pursuant to procedures set forth in the Participant Agreement.

If on the settlement date (typically T+2) an Authorized Participant has failed to deliver all of the Vanguard ETF Shares it is seeking to redeem, the ETF Fund shall be entitled to cancel the redemption order. Alternatively, the ETF Fund may deliver to the Authorized Participant the full complement of Redemption Securities and cash in reliance on the Authorized Participant's undertaking to deliver the missing ETF Shares at a later date. Such undertaking shall be secured by the Authorized Participant's delivery and maintenance of cash collateral in accordance with collateral procedures that are part of the Participant Agreement. In all cases the ETF Fund shall be entitled to charge the Authorized Participant for any costs (including investment losses, attorney's fees, and interest) incurred by the ETF Fund as a result of the late delivery or failure to deliver.

If an Authorized Participant, or a redeeming investor acting through an Authorized Participant, is subject to a legal restriction with respect to a particular security included in the basket of Redemption Securities, such investor may be paid an equivalent amount of cash in lieu of the security. In addition, each ETF Fund reserves the right to redeem Creation Units partially for cash to the extent that the Fund could not lawfully deliver one or more Redemption Securities or could not do so without first registering such securities under federal or state law.

Suspension of Redemption Rights. The right of redemption may be suspended or the date of payment postponed with respect to an ETF Fund (1) for any period during which the NYSE or listing exchange is closed (other than customary weekend and holiday closings), (2) for any period during which trading on the NYSE or listing exchange is suspended or restricted, (3) for any period during which an emergency exists as a result of which disposal of the Fund's portfolio securities or determination of its NAV is not reasonably practicable, or (4) in such other circumstances as the SEC permits.

Precautionary Notes

A precautionary note to ETF investors: The DTC or its nominee will be the registered owner of all outstanding ETF Shares. Your ownership of ETF Shares will be shown on the records of the DTC and the DTC Participant broker through which you hold the shares. Vanguard will not have any record of your ownership. Your account information will be maintained by your broker, which will provide you with account statements, confirmations of your purchases and sales of ETF Shares, and tax information. Your broker also will be responsible for distributing income and capital gains distributions and for ensuring that you receive shareholder reports and other communications from the fund whose ETF Shares you own. You will receive other services (e.g., dividend reinvestment and average cost information) only if your broker offers these services.

You should also be aware that investments in ETF Shares may be subject to certain risks relating to having large shareholders. To the extent that a large number of the Fund's ETF Shares are held by a large shareholder (e.g., an institutional investor, an investment advisor or an affiliate of an investment advisor, an authorized participant, a lead market maker, or another entity), a large redemption by such a shareholder could result in an increase in the ETF's expense ratio, cause the ETF to incur higher transaction costs, cause the ETF to fail to comply with applicable listing standards of the listing exchange upon which it is listed, lead to the realization of taxable capital gains, or cause the remaining shareholders to receive distributions representing a disproportionate share of the ETF's ordinary income and long-term capital gains. In addition, transactions by large shareholders may account for a large percentage of the trading volume on an exchange and may, therefore, have a material upward or downward effect on the market price of the ETF Shares.

A precautionary note to purchasers of Creation Units: You should be aware of certain legal risks unique to investors purchasing Creation Units directly from the issuing fund.

Because new ETF Shares may be issued on an ongoing basis, a "distribution" of ETF Shares could be occurring at any time. Certain activities that you perform as a dealer could, depending on the circumstances, result in your being deemed a participant in the distribution in a manner that could render you a statutory underwriter and subject you to the prospectus delivery and liability provisions of the Securities Act of 1933 (the 1933 Act). For example, you could be deemed a statutory underwriter if you purchase Creation Units from the issuing fund, break them down into the constituent ETF Shares, and sell those shares directly to customers or if you choose to couple the creation of a supply of new ETF Shares with an active selling effort involving solicitation of secondary market demand for ETF Shares. Whether a person is an underwriter depends upon all of the facts and circumstances pertaining to that person's activities, and the examples mentioned here should not be considered a complete description of all the activities that could cause you to be deemed an underwriter.

Dealers who are not "underwriters" but are participating in a distribution (as opposed to engaging in ordinary secondary- market transactions), and thus dealing with ETF Shares as part of an "unsold allotment" within the meaning of Section 4(3)(C) of the 1933 Act, will be unable to take advantage of the prospectus delivery exemption provided by Section 4(3) of the 1933 Act.

A precautionary note to shareholders redeeming Creation Units: An Authorized Participant that is not a "qualified institutional buyer" as defined in Rule 144A under the 1933 Act will not be able to receive, as part of the redemption basket, restricted securities eligible for resale under Rule 144A.

A precautionary note to investment companies: Vanguard ETF Shares are issued by registered investment companies, and therefore the acquisition of such shares by other investment companies and private funds is subject to the restrictions of Section 12(d)(1) of the 1940 Act. SEC Rule 12d1-4 under the 1940 Act permits investments in Vanguard ETF Shares beyond the limits of Section 12(d)(1), subject to the conditions of Rule 12d1-4, as described

under the heading "Other Investment Companies."

FINANCIAL STATEMENTS

As of the Date of this SAI, Vanguard 0-3 Month Treasury Bill ETF and Vanguard Ultra-Short Treasury ETF had not commenced operations, and therefore financial statements are not yet available for the Funds. For a more complete discussion of the Funds' performance, please see the Funds' annual and semiannual reports to shareholders, which, once available, may be obtained without charge."

DESCRIPTION OF BOND RATINGS

Moody's Rating Symbols

The following describe characteristics of the global long-term (original maturity of 1 year or more) bond ratings provided by Moody's Investors Service, Inc. (Moody's):

Aaa-Judged to be obligations of the highest quality, they are subject to the lowest level of credit risk.

Aa-Judged to be obligations of high quality, they are subject to very low credit risk. Together with the Aaa group, they make up what are generally known as high-grade bonds.

A-Judged to be upper-medium-grade obligations, they are subject to low credit risk.

Baa-Judged to be medium-grade obligations, subject to moderate credit risk, they may possess certain speculative characteristics.

Ba-Judged to be speculative obligations, they are subject to substantial credit risk. B-Considered to be speculative obligations, they are subject to high credit risk.

Caa-Judged to be speculative obligations of poor standing, they are subject to very high credit risk.

Ca-Viewed as highly speculative obligations, they are likely in, or very near, default, with some prospect of recovery of principal and interest.

C-Viewed as the lowest rated obligations, they are typically in default, with little prospect for recovery of principal and interest.

Moody's also supplies numerical indicators (1, 2, and 3) to rating categories. The modifier 1 indicates that the security is in the higher end of its rating category, the modifier 2 indicates a mid-range ranking, and the modifier 3 indicates a ranking toward the lower end of the category.

The following describe characteristics of the global short-term (original maturity of 13 months or less) bond ratings provided by Moody's. This ratings scale also applies to U.S. municipal tax-exempt commercial paper.

Prime-1 (P-1)-Judged to have a superior ability to repay short-term debt obligations.

Prime-2 (P-2)-Judged to have a strong ability to repay short-term debt obligations.

Prime-3 (P-3)-Judged to have an acceptable ability to repay short-term debt obligations.

Not Prime (NP)-Cannot be judged to be in any of the prime rating categories.

The following describe characteristics of the U.S. municipal short-term bond ratings provided by Moody's:

Moody's ratings for state and municipal notes and other short-term (up to 3 years) obligations are designated Municipal Investment Grade (MIG).

MIG 1-Indicates superior quality, enjoying the excellent protection of established cash flows, liquidity support, and broad- based access to the market for refinancing.

MIG 2-Indicates strong credit quality with ample margins of protection, although not as large as in the preceding group.

MIG 3-Indicates acceptable credit quality, with narrow liquidity and cash-flow protection and less well-established market access for refinancing.

SG-Indicates speculative credit quality with questionable margins of protection.

Standard and Poor's Rating Symbols

The following describe characteristics of the long-term (original maturity of 1 year or more) bond ratings provided by Standard and Poor's:

AAA-These are the highest rated obligations. The capacity to pay interest and repay principal is extremely strong.

AA-These also qualify as high-grade obligations. They have a very strong capacity to pay interest and repay principal, and they differ from AAA issues only in small degree.

A-These are regarded as upper-medium-grade obligations. They have a strong capacity to pay interest and repay principal although they are somewhat more susceptible to the adverse effects of changes in circumstances and economic conditions than debt in higher-rated categories.

BBB-These are regarded as having an adequate capacity to pay interest and repay principal. However, adverse economic conditions or changing circumstances are more likely to lead to a weakened capacity in this regard. This group is the lowest that qualifies for commercial bank investment.

BB, B, CCC, CC, and C-These obligations range from speculative to significantly speculative with respect to the capacity to pay interest and repay principal. BB indicates the lowest degree of speculation and C the highest.

D-These obligations are in default, and payment of principal and/or interest is likely in arrears.

The ratings from AA to CCC may be modified by the addition of a plus (+) or minus (-) sign to show relative standing within the major rating categories.

The following describe characteristics of short-term (original maturity of 365 days or less) bond and commercial paper ratings designations provided by Standard and Poor's:

A-1-These are the highest rated obligations. The capacity of the obligor to pay interest and repay principal is strong. The addition of a plus sign (+) would indicate a very strong capacity.

A-2-These obligations are somewhat susceptible to changing economic conditions. The obligor has a satisfactory capacity to pay interest and repay principal.

A-3-These obligations are more susceptible to the adverse effects of changing economic conditions, which could lead to a weakened capacity to pay interest and repay principal.

B-These obligations are vulnerable to nonpayment and are significantly speculative, but the obligor currently has the capacity to meet its financial commitments.

C-These obligations are vulnerable to nonpayment, but the obligor must rely on favorable economic conditions to meet its financial commitment.

D-These obligations are in default, and payment of principal and/or interest is likely in arrears.

The following describe characteristics of U.S. municipal short-term (original maturity of 3 years or less) note ratings provided by Standard and Poor's:

SP-1-This designation indicates a strong capacity to pay principal and interest.

SP-2-This designation indicates a satisfactory capacity to pay principal and interest.

SP-3-This designation indicates a speculative capacity to pay principal and interest.

APPENDIX A

Summary of the Vanguard-Advised Funds Proxy Voting Policy

The funds for which Vanguard acts as investment advisor (Vanguard-advised funds) retain authority to vote proxies received for the shares of equity securities held in each fund. The Board of Trustees (the Board) for the Vanguard-advised funds has adopted proxy voting procedures and guidelines to govern proxy voting for each portfolio retaining proxy voting authority.

The Investment Stewardship Oversight Committee (the Committee), comprised primarily of fund officers and subject to the procedures described below, oversees the Vanguard-advised funds' proxy voting. The Committee reports directly to the Board. Vanguard is subject to these procedures and the proxy voting policies to the extent that they call for Vanguard to administer the voting process and implement the resulting voting decisions, and for these purposes the voting policies have also been approved by the Board of Directors of Vanguard.

The voting principles and policies adopted by the Board provide a framework for assessing each proposal and seek to ensure that each vote is cast in the best interests of each fund. Under the voting policies, each proposal is evaluated on its merits, based on the particular facts and circumstances presented at the company in question. For more information on the funds' proxy voting policies, please visit about.vanguard.com/investment-stewardship.

I. Investment Stewardship Team

The Investment Stewardship Team administers the day-to-day operation of the funds' proxy voting process, overseen by the Committee. The Investment Stewardship Team performs the following functions: (1) managing and conducting due diligence of proxy voting vendors; (2) reconciling share positions; (3) analyzing proxy proposals using factors described in the voting policies; (4) determining and addressing potential or actual conflicts of interest that may be presented by a

particular proxy; and (5) voting proxies. The Investment Stewardship Team also prepares periodic and special reports for the Board and proposes amendments to the procedures and voting policies.

II. Investment Stewardship Oversight Committee

The Board, including a majority of the independent trustees, appoints the members of the Committee (which is comprised primarily of fund officers). The Committee works with the Investment Stewardship Team to provide reports and other guidance to the Board regarding proxy voting by the funds. The Committee has an obligation to exercise its decision- making authority in accordance with the Board's instructions as set forth in the funds' proxy voting procedures and voting policies and subject to the fiduciary standards of good faith, fairness, and Vanguard's Code of Ethical Conduct. The Committee may advise the Investment Stewardship Team on how to best apply the Board's instructions as set forth in the voting policies or refer the matter to the Board, which has ultimate decision-making authority for the funds. The Board reviews the procedures and voting policies annually and modifies them from time to time upon the recommendation of the Committee and in consultation with the Investment Stewardship Team.

III. Proxy Voting Pillars

Vanguard's investment stewardship activities are grounded in four pillars of corporate governance:

1)Board composition and effectiveness: Good governance begins with a company's board of directors. Our primary focus is on understanding to what extent the individuals who serve as board members are appropriately independent, capable, and experienced.

2)Board oversight of strategy and risk: Boards should be meaningfully involved in the formation and oversight of strategy and have ongoing oversight of material risks to their company. We work to understand how boards of directors are involved in strategy formation, oversee company strategy, and identify and govern material risks to long-term shareholder returns.

3)Executive pay (compensation or remuneration): Sound, performance-linked compensation programs drive long-term investment returns. We look for companies to provide clear disclosure about their compensation practices, the board's oversight of those practices, and how said practices are aligned with long-term shareholder returns.

4)Shareholder rights: We believe governance structures should allow shareholders to effectively exercise their foundational rights. Shareholder rights enable a company's owners to use their voice and their vote - ideally, consistent with their economic exposure - to effect and approve changes in corporate governance practices.

IV. Evaluation of Proxies

For ease of reference, the procedures and guidelines often refer to all Vanguard-advised funds. However, the processes and practices seek to ensure that proxy voting decisions are suitable for individual funds. For most proxy proposals, particularly those involving routine corporate governance matters, the evaluation could result in the funds having a common interest in the matter and, accordingly, each fund casting votes in the same manner. In other cases, however, a fund may vote differently from other funds, depending upon the nature and objective of each fund, if doing so is in the best interest of the individual fund.

The voting policies do not permit the Board to delegate voting discretion to a third party that does not serve as a fiduciary for all Vanguard-advised funds. Because many factors bear on each decision, the voting policies incorporate factors that should be considered in each voting decision. A fund may refrain from voting some or all of its shares or vote in a particular way if doing so would be in the fund's and its shareholders' best interests. These circumstances may arise, for example, if the expected cost of voting exceeds the expected benefits of voting, if exercising the vote would result in the imposition of trading or other restrictions, or if a fund (or all Vanguard funds in the aggregate) were to own more than the permissible maximum percentage of a company's stock (as determined by the company's governing documents or by applicable law, regulation, or regulatory agreement), or if voting would present a potential conflict of interest.

In evaluating proxy proposals, the Investment Stewardship Team considers information from many sources, which could include, but is not limited to, the perspectives of the company management or shareholders presenting a proposal, independent proxy research services, or proprietary research. Additionally, data and recommendations from proxy advisors serve as one of many inputs into our research process. The Vanguard-advised funds may utilize automated voting for matters that are clearly addressed by the funds' proxy voting procedures and guidelines.

While serving as a framework, the voting policies cannot contemplate all possible proposals with which a fund may be presented. In the absence of a specific guideline for a particular proposal (e.g., in the case of a transactional issue or contested proxy), the Investment Stewardship Team, under the supervision of the Committee, will evaluate the matter and cast the fund's vote in a manner that is in the fund's best interest, subject to the individual circumstances of the fund.

V. Conflicts of Interest

Vanguard takes seriously its commitment to avoid potential conflicts of interest. Vanguard funds invest in thousands of publicly listed companies worldwide. Those companies may include clients, potential clients, vendors, or competitors. Some companies may employ Vanguard trustees, former Vanguard executives, or family members of Vanguard personnel who have direct involvement in Vanguard's Investment Stewardship program.

Vanguard's approach to mitigating conflicts of interest begins with the funds' proxy voting procedures. The procedures require that voting personnel act as fiduciaries and must conduct their activities at all times in accordance with the following standards: (i) fund shareholders' interests come first; (ii) conflicts of interest must be avoided and mitigated to the extent possible; and (iii) compromising situations must be avoided.

We maintain an important separation between Vanguard's Investment Stewardship Team and other groups within Vanguard that are responsible for sales, marketing, client service, and vendor/partner relationships. Proxy voting personnel are required to disclose potential conflicts of interest and must recuse themselves from all voting decisions and engagement activities in such instances. In certain circumstances, Vanguard may refrain from voting shares of a company, or may engage an independent third-party fiduciary to vote proxies.

Each externally managed fund has adopted the proxy voting guidelines of its advisor(s) and votes in accordance with the external advisors' guidelines and procedures. Each advisor has its own procedures for managing conflicts of interest in the best interests of fund shareholders.

VI. Shareholder Proposals

Shareholder proposals are evaluated in the context of the general corporate governance principle that a company's board has ultimate responsibility for providing effective ongoing oversight of relevant sector and company-specific risks, including risks related to environmental and social matters. Each proposal is evaluated on its merits and in the context of the particular facts and circumstances at the company in question and supported when there is a logically demonstrable linkage between the specific proposal and long-term shareholder value of the company. Some of the factors considered when evaluating shareholder proposals include the materiality of the risk addressed by the proposal, the quality of the current disclosures/business practices, and any progress by the company toward addressing and disclosing the relevant material risk.

VII. Voting in Markets Outside the United States

Corporate governance standards, disclosure requirements, and voting mechanics vary greatly among the markets outside the United States (U.S.) in which the funds may invest. Each fund's votes will be used, where applicable, to support improvements in governance and disclosure by each fund's portfolio companies. Matters presented by non-U.S. portfolio companies will be evaluated in the foregoing context, as well as in accordance with local market standards and best practices. Votes are cast for each fund in a manner philosophically consistent with the voting policies, taking into account differing practices by market.

In many other markets, voting proxies will result in a fund being prohibited from selling the shares for a period of time due to requirements known as "share-blocking" or reregistration. Generally, the value of voting is unlikely to outweigh the loss of liquidity imposed by these requirements on the funds. In such instances, the funds will generally abstain from voting.

The costs of voting (e.g., custodian fees, vote agency fees) in other markets may be substantially higher than for U.S. holdings. As such, the fund may limit its voting on foreign holdings in instances in which the issues presented are unlikely to have a material impact on shareholder value.

VIII. Voting Shares of a Company That Has an Ownership Limitation

Certain companies have provisions in their governing documents or other agreements that restrict stock ownership in excess of a specified limit. Typically, these ownership restrictions are included in the governing documents of real estate investment trusts but may be included in other companies' governing documents. A company's governing documents normally allow the company to grant a waiver of these ownership limits, which would allow a fund to exceed the stated ownership limit. Sometimes a company will grant a waiver without restriction. From time to time, a company may grant a waiver only if a fund (or funds) agrees to not vote the company's shares in excess of the normal specified limit. In such a circumstance, a fund may refrain from voting shares if owning the shares beyond the company's specified limit is in the best interests of the fund and its shareholders.

SIGNATURES

Pursuant to the requirements of the Securities Act of 1933 and the Investment Company Act of 1940, the Registrant has duly caused this Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the Town of Valley Forge and the Commonwealth of Pennsylvania, on the 22nd day of November, 2024.

VANGUARD INSTITUTIONAL INDEX FUNDS

BY: /s/ Salim Ramji*

Salim Ramji

Chief Executive Officer

Pursuant to the requirements of the Securities Act of 1933, this Post-Effective Amendment to the Registration Statement has been signed below by the following persons in the capacities and on the date indicated:

*By: /s/ John E. Schadl

John E. Schadl, pursuant to a Power of Attorney filed on July 25, 2024 (see File Number 33-48863), Incorporated by Reference.