Summary Prospectus by Investment Company - Form 497K

US equity mutual fund

Delaware Ivy Mid Cap Growth Fund

July 31, 2024

(to be renamed Macquarie Mid Cap Growth Fund on or about December 31, 2024)

What is the Fund's investment objective?

Delaware Ivy Mid Cap Growth Fund seeks to provide growth of capital.

What are the Fund's fees and expenses?

The table below describes the fees and expenses that 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 examples below. You may qualify for sales-charge discounts if you and your family invest, or agree to invest in the future, at least $50,000 in Delaware Funds by Macquarie​® (to be renamed Macquarie Funds on or about December 31, 2024). More information about these and other discounts is available from your financial intermediary, in the Fund's Prospectus under the section entitled "About your account," and in the Fund's statement of additional information (SAI) under the section entitled "Purchasing Shares."

Shareholder fees (fees paid directly from your investment)

Annual fund operating expenses (expenses that you pay each year as a percentage of the value of your investment)

Example

This example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of your shares at the end of those periods. In addition, the example shows expenses for Class C shares, assuming those shares were not redeemed at the end of those periods. The example also assumes that your investment has a 5% return each year and reflects the Manager's expense waivers and reimbursements for the 1-year contractual period and the total operating expenses without waivers for years 2 through 10. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

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 higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in the annual fund operating expenses or in the example, affect the Fund's performance. During the most recent fiscal year, the Fund's portfolio turnover rate was 27% of the average value of its portfolio.

What are the Fund's principal investment strategies?

Delaware Ivy Mid Cap Growth Fund seeks to achieve its objective by investing primarily in common stocks of mid-capitalization companies that the Manager believes are high quality and/or offer above-average growth potential. Under normal circumstances, the Fund invests at least 80% of its net assets in the securities of mid-capitalization companies, which, for purposes of this Fund, typically are companies with market capitalizations similar to those of issuers included in the Russell Midcap​® Growth Index over the last 13 months at the time of acquisition. As of July 1, 2024, this range of market capitalizations was between approximately $641 million and $59.1 billion.

In selecting securities for the Fund, the Manager primarily emphasizes a bottom-up (researching individual issuers) approach and focuses on companies it believes have the potential for strong growth, increasing profitability, stable and sustainable revenue and earnings streams, attractive valuations and sound capital structures. The Manager may look at a number of factors in its consideration of a company, such as: new or innovative products or services; adaptive or creative management; strong financial and operational capabilities to sustain multi-year growth; stable and consistent revenue, earnings, and cash flow; strong balance sheet; market potential; and profit potential. Part of the Manager's investment process also includes a review of the macroeconomic environment, with a focus on factors such as interest rates, inflation, consumer confidence and corporate spending.

Generally, in determining whether to sell a security, the Manager considers many factors, including what it believes to be excessive valuation given company growth prospects, deterioration of fundamentals, weak cash flow to support shareholder returns, and unexpected and poorly explained management changes. The Manager also may sell a security to reduce the Fund's holding in that security, to take advantage of what it believes are more attractive investment opportunities or to raise cash.

The Manager may permit its affiliate, Macquarie Investment Management Global Limited (MIMGL), to execute Fund security trades on behalf of the Manager. The Manager may also seek quantitative support from MIMGL.

What are the principal risks of investing in the Fund?

Investing in any mutual fund involves the risk that you may lose part or all of the money you invest. Over time, the value of your investment in the Fund will increase and decrease according to changes in the value of the securities in the Fund's portfolio. An investment in the Fund may not be appropriate for all investors. The Fund's principal risks include:

Market risk - The risk that all or a majority of the securities in a certain market - such as the stock or bond market - will decline in value because of factors such as adverse political or economic conditions, future expectations, investor confidence, or heavy institutional selling.

Growth stock risk -Growth stocks reflect projections of future earnings and revenue. These prices may rise or fall dramatically depending on whether those projections are met. These companies' stock prices may be more volatile, particularly over the short term.

Small- and mid-market capitalization company risk - The risk that investments in small- and/or medium-sized companies may bemore volatile than those of larger companies because of limited financial resources or dependence on narrow product lines.

Information technology sector risk - The risk that investment risks associated with investing in the information technology sector, in addition to other risks, include the intense competition to which information technology companies may be subject; the dramatic and often unpredictable changes in growth rates and competition for qualified personnel among information technology companies;

effects on profitability from being heavily dependent on patent and intellectual property rights and the loss or impairment of those rights; obsolescence of existing technology; general economic conditions; and government regulation.

Industry and sector risk - The risk that the value of securities in a particular industry or sector (such as information technology) will decline because of changing expectations for the performance of that industry or sector.

Healthcare sector risk - The risk that the value of a fund's shares will be affected by factors particular to the healthcare and related sectors (such as government regulation) and may fluctuate more widely than that of a fund that invests in a broad range of sectors.

Liquidity risk - The possibility that investments cannot be readily sold within seven calendar days at approximately the price at which a fund has valued them.

Active management and selection risk - The risk that the securities selected by a fund's management will underperform the markets, the relevant indices, or the securities selected by other funds with similar investment objectives and investment strategies. The securities and sectors selected may vary from the securities and sectors included in the relevant index.

None of the entities noted in this document is an authorized deposit-taking institution for the purposes of the Banking Act 1959 (Commonwealth of Australia) and the obligations of these entities do not represent deposits or other liabilities of Macquarie Bank Limited ABN 46 008 583 542 (Macquarie Bank). Macquarie Bank does not guarantee or otherwise provide assurance in respect of the obligations of these entities. In addition, if this document relates to an investment (a) each investor is subject to investment risk including possible delays in repayment and loss of income and principal invested and (b) none of Macquarie Bank or any other Macquarie Group company guarantees any particular rate of return on or the performance of the investment, nor do they guarantee repayment of capital in respect of the investment.

How has Delaware Ivy Mid Cap Growth Fund performed?

The bar chart and table below provide some indication of the risks of investing in the Fund by showing changes in the Fund's performance from year to year and by showing how the Fund's average annual total returns for the 1-, 5-, and 10-year or lifetime periods compare with those of a broad measure of market performance and an additional index with characteristics relevant to the Fund. On April 30, 2021, the Fund became part of Delaware Funds by Macquarie​® and Delaware Management Company became the Fund's investment manager. The returns shown from before April 30, 2021 are from the Fund's prior investment manager. The Fund's past performance (before and after taxes) is not necessarily an indication of how it will perform in the future. The returns reflect any expense caps in effect during these periods. The returns would be lower without the expense caps. You may obtain the Fund's most recently available month-end performance by calling 800 523-1918 or by visiting our website at delawarefunds.com/performance.

Calendar year-by-year total return (Class A)

As of June 30, 2024, the Fund's Class A shares had a calendar year-to-date return of 0.80%. During the periods illustrated in this bar chart, Class A's highest quarterly return was 37.07% for the quarter ended June 30, 2020, and its lowest quarterly return was -21.85% for the quarter ended June 30, 2022. The maximum Class A sales charge of 5.75%, which is normally deducted when you purchase shares, is not reflected in the highest/lowest quarterly returns or in the bar chart. If this fee were included, the returns would be less than those shown. The average annual total returns in the table below do include the sales charge.

Average annual total returns for periods ended December 31, 2023

* In connection with new regulatory requirements, effective July 31, 2024, the Fund changed its broad-based securities market benchmark index from the Russell Midcap Growth Index to the Russell 3000 Index. Although the Fund will continue to show the performance of the Russell Midcap Growth Index for comparative purposes, the Russell 3000 Index can be considered more broadly representative of the overall securities market applicable to the Fund.

Frank Russell Company is the source and owner of the trademarks, service marks, and copyrights related to the Russell Indexes. Russell​® is a trademark of Frank Russell Company.

After-tax performance is presented only for Class A shares of the Fund. The after-tax returns for other Fund classes may vary. Actual after-tax returns depend on the investor's individual tax situation and may differ from the returns shown. After-tax returns are not relevant for shares held in tax-advantaged investment vehicles such as employer-sponsored 401(k) plans and individual retirement accounts (IRAs). The after-tax returns shown are calculated using the highest individual federal marginal income tax rates in effect during the periods presented and do not reflect the impact of state and local taxes.

Who manages the Fund?

Investment manager

Delaware Management Company, a series of Macquarie Investment Management Business Trust (a Delaware statutory trust)

Sub-advisor

Macquarie Investment Management Global Limited

Purchase and redemption of Fund shares

You may purchase or redeem shares of the Fund on any day that the New York Stock Exchange (NYSE) is open for business (Business Day). Shares may be purchased or redeemed: through your financial intermediary; through the Fund's website at delawarefunds.com/account-access; by calling 800 523-1918; by regular mail (c/o Delaware Funds by Macquarie​®, P.O. Box 534437, Pittsburgh, PA 15253-4437); by overnight courier service (c/o Delaware Funds by Macquarie Service Center, Attention: 534437, 500 Ross Street, 154-0520, Pittsburgh, PA 15262); or by wire.

For Class A and Class C shares, the minimum initial investment is generally $1,000 and subsequent investments can be made for as little as $100. The minimum initial investment for IRAs, Uniform Gifts/Transfers to Minors Act accounts, direct deposit purchase plans, and automatic investment plans is $250 and through Coverdell Education Savings Accounts is $500, and subsequent investments in these accounts can be made for as little as $25. For Class R, Class I, Class Y, and Class R6 shares (except those shares purchased through an automatic investment plan), there is no minimum initial purchase requirement, but certain eligibility requirements must be met. The eligibility requirements are described in this Prospectus under "Choosing a share class" and on the Fund's website. We may reduce or waive the minimums or eligibility requirements in certain cases.

Please refer to the Fund's prospectus and statement of additional information for more details regarding the purchase and sale of Fund shares.

Tax information

The Fund's distributions generally are taxable to you as ordinary income, capital gains, or some combination of both, unless you are investing through a tax-advantaged arrangement, such as a 401(k) plan or an IRA, in which case your distributions may be taxed as ordinary income when withdrawn from the tax-advantaged account.

Payments to broker/dealers and other financial intermediaries

If you purchase shares of the Fund through a broker/dealer or other financial intermediary (such as a bank), the Fund and its related companies may pay the intermediary for the sale of Fund shares and related services. These payments may create a conflict of interest by influencing the broker/dealer or other intermediary and your salesperson to recommend the Fund over another investment. Ask your salesperson or visit your financial intermediary's website for more information.