Summary Prospectus by Investment Company - Form 497K

Before you invest, you may want to review the Fund's prospectus, which contains more information about the Fund and its risks. You can find the Fund's Prospectus and Statement of Additional Information ("SAI") and other information about the Fund online at https://www.aamlive.com/publicsite/mutual-funds-detail-himco. You may also obtain this information at no cost by calling 1-888-966-9661 or by sending an e-mail request to [email protected]. The Fund's Prospectus and SAI, both dated October31, 2024 (as each may be further amended or supplemented), are incorporated by reference into this Summary Prospectus.

Investment Objectives

The investment objectives of the AAM/HIMCO Short DurationFund (the "Fund") are to seek to provide current income and long-term total return.

Fees and Expenses of the Fund

This table 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 table and example below. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $100,000 in Class A shares of the Fund. More information about these and other discounts is available from your financial professional and in the section titled "YOUR ACCOUNT WITH THE FUND - Purchase of Shares/Class A Shares" on page 29 of the Prospectus and in "APPENDIX A - Waivers and Discounts Available from Intermediaries" of the Prospectus.

1.For Class A Shares, no sales charge applies on investments of $1 million or more, but a contingent deferred sales charge ("CDSC") of 1.00% will be imposed to the extent a finder's fee was paid on certain redemptions of such shares within 18 months of the date of purchase. Class C Shares of the Fund are subject to a CDSC of 1.00% on any shares sold within 12 months of purchasing them.

2.The total annual fund operating expenses do not correlate to the ratio of expense to average net assets appearing in the financial highlights table, which reflects only the operating expenses of the Fund and does not include acquired fund fees and expenses.

3.The Fund's advisor has contractually agreed to waive its fees and/or pay for operating expenses of the Fund to ensure that total annual fund operating expenses (excluding, as applicable, taxes, leverage interest, brokerage commissions, dividend and interest expenses on short sales, acquired fund fees and expenses (as determined in accordance with Form N-1A), expenses incurred in connection with any merger or reorganization and extraordinary expenses such as litigation expenses) do not exceed 0.84%, 1.59% and 0.59% of the average daily net assets of the Class A Shares, Class C Shares and Class I Shares, respectively. This agreement is in effect through October 31, 2034, and may be terminated before that date only by the Trust's Board of Trustees. The Fund's advisor is permitted to seek reimbursement from the Fund for a period ending three full fiscal years after the date of the waiver or payment. This reimbursement may be requested from the Fund if the reimbursement will not cause the Fund's annual expense ratio to exceed the lesser of (a) the expense limitation in effect at the time such fees were waived or payments made, or (b) the expense limitation in effect at the time of the reimbursement.

Example

This example is intended to help you compare the costs 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. The example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain the same. The example reflects the Fund's contractual fee waiver and/or expense reimbursement for the term of the contractual fee waiver and/or expense reimbursement.

Although your actual costs may be higher or lower, based on these assumptions your costs would be:

You would pay the following expenses on Class C Shares if you did not redeem your shares:

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 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 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 33% of the average value of its portfolio.

Principal Investment Strategies

The Fund seeks to achieve its investment objectives by investing in securities that the Fund's sub-advisor, Hartford Investment Management Company ("HIMCO" or the "Sub-Advisor"), considers to be attractive, based on current and historical yield and total return. The Fund has an investment policy whereby at least 80% of the Fund's net assets (plus any borrowings for investment purposes) will be invested, under normal circumstances, in fixed income instruments. This policy may be changed by the Board of Trustees without shareholder approval. The Fund normally invests at least 65% of its total assets in "investment grade" securities. The Fund may invest up to 35% of its total assets in non-investment grade securities (often called "junk bonds"), as well as bank loans and loan participation interests. "Investment grade" quality securities and instruments refer to securities or other instruments that are rated at the time of purchase within the four highest categories assigned by Moody's Investor Services, Inc. ("Moody's") ("Aaa", "Aa", "A" or "Baa"), Standard & Poor's ("S&P") ("AAA", "AA", "A" or "BBB") or Fitch, Inc. ("Fitch") ("AAA", "AA", "A" or "BBB") or are unrated securities or other instruments that are judged by the Sub-Advisor to be of comparable credit quality to securities rated within these four highest categories. In the case of "split-rated" securities or loans (i.e., securities or loans assigned non-equivalent credit quality ratings, such as Baa by Moody's but BB by S&P or Aa by Moody's and AA by S&P but B by Fitch), the Sub-Advisor will determine whether a particular security or loan is considered investment grade or below-investment grade for the Fund as follows: (a) if all three credit rating agencies have rated a security or loan, the median credit rating will be used for this determination; (b) if only two credit rating agencies have rated a security, the lower (e.g., most conservative) credit rating will be used; and (c) if only one credit rating agency has rated a security that agency's rating is used. The Fund will normally maintain a dollar weighted average duration and an average maturity (as measured by a weighted average life calculation) of less than 3 years. The weighted average life of the Fund is the average time to receipt of principal of each security weighted by such security's respective contribution to the total market value of the Fund, including principal and accrued interest. The Fund's permitted investments include, but are not limited to, corporate securities, commercial mortgage-backed securities, asset-backed securities, mortgage related securities, collateralized loan obligations, sovereign debt securities, emerging market securities, municipal securities, and securities issued or guaranteed as to principal or interest by the U.S. government, its agencies or instrumentalities. The Fund may also invest up to 25% of its total assets in the securities of foreign issuers and may trade securities actively. The Fund's investments will be U.S. dollar denominated. The Fund may make significant investments in certain sectors or group of sectors from time to time. The Fund may utilize derivatives, such as swaps, futures and options for hedging purposes.

In selecting securities for the Fund's portfolio, the Sub-Advisor uses a top-down, bottom-up approach, combining macro analysis of market and economic trends and individual security analysis.

Principal Risks of Investing

Risk is inherent in all investing and you could lose money by investing in the Fund. A summary description of certain principal risks of investing in the Fund is set forth below. Before you decide whether to invest in the Fund, carefully consider these risk factors associated with investing in the Fund, which may cause investors to lose money. There can be no assurance that the Fund will achieve its investment objectives.

Market Risk. The market price of a security or instrument may decline, sometimes rapidly or unpredictably, due to general market conditions that are not specifically related to a particular company, such as real or perceived adverse economic, political, or geopolitical conditions throughout the world, changes in the general outlook for corporate earnings, changes in interest or currency rates, or adverse investor sentiment generally. The market value of a security or instrument also may decline because of factors that affect a particular industry or industries, such as labor shortages or increased production costs and competitive conditions within an industry. In addition, local, regional or global events such as war, acts of terrorism, international conflicts, trade disputes, supply chain disruptions, cybersecurity events, the spread of infectious illness or other public health issues, natural disasters or climate events, or other events could have a significant impact on a security or instrument. The increasing interconnectivity between global economies and financial markets increases the likelihood that events or conditions in one region or financial market may adversely impact issuers in a different country, region or financial market.

Fixed Income Securities Risk. The prices of fixed income securities respond to economic developments, particularly interest rate changes, as well as to changes in an issuer's credit rating or market perceptions about the creditworthiness of an issuer. Generally, fixed income securities decrease in value if interest rates rise and increase in value if interest rates fall, and longer-term and lower rated securities are more volatile than shorter-term and higher rated securities.

Credit Risk. If an issuer or guarantor of a debt security held by the Fund or a counterparty to a financial contract with the Fund defaults or is downgraded or is perceived to be less creditworthy, or if the value of the assets underlying a security declines, the value of the Fund's portfolio will typically decline. Subordinated securities are more likely to suffer a credit loss than non-subordinated securities of the same issuer and will be disproportionately affected by a default, downgrade or perceived decline in creditworthiness.

Interest Rate Risk. Prices of fixed income securities tend to move inversely with changes in interest rates.Generally, fixed income securities decrease in value if interest rates rise and increase in value if interest rates fall, with longer-term securities being more sensitive than shorter-term securities. For example, the price of a security with a three-year duration would be expected to drop by approximately 3% in response to a 1% increase in interest rates. Generally, the longer the maturity and duration of a bond or fixed rate loan, the more sensitive it is to this risk. Falling interest rates also create the potential for a decline in the Fund's income. Changes in governmental policy, rising inflation rates, and general economic developments, among other factors, could cause interest rates to increase and could have a substantial and immediate effect on the values of the Fund's investments. In addition, a potential rise in interest rates may result in periods of volatility and increased redemptions that might require the Fund to liquidate portfolio securities at disadvantageous prices and times.

Liquidity Risk. The Fund may not be able to sell some or all of the investments that it holds due to a lack of demand in the marketplace or other factors such as market turmoil, or if the Fund is forced to sell an illiquid asset to meet redemption requests or other cash needs it may only be able to sell those investments at a loss. In addition, the reduction in dealer market-making capacity in the fixed income markets that has occurred in recent years has the potential to decrease the liquidity of the Fund's investments. Illiquid assets may also be difficult to value.

Event Risk. Event risk is the risk that corporate issuers may undergo restructurings, such as mergers, leveraged buyouts, takeovers, or similar events financed by increased debt. As a result of the added debt, the credit quality and market value of a company's bonds and/or other debt securities may decline significantly.

High Yield ("Junk") Bond Risk. High yield bonds are debt securities rated below investment grade (often called "junk bonds"). Junk bonds are speculative, involve greater risks of default, downgrade, or price declines and are more volatile and tend to be less liquid than investment-grade securities. Companies issuing high yield bonds are less financially strong, are more likely to encounter financial difficulties, and are more vulnerable to adverse market events and negative sentiments than companies with higher credit ratings.

Bank Loans and Loan Participations Risk. Bank loans and loan participations are subject to credit risk, including the risk of nonpayment of principal or interest. Also, substantial increases in interest rates may cause an increase in loan defaults. Although the loans may be fully collateralized at the time of acquisition, the collateral may decline in value, be relatively illiquid, or lose all or substantially all of its value subsequent to investment. In addition, in the event an agent bank becomes insolvent, a bank loan could be subject to settlement risks or administrative disruptions that could adversely affect the Fund's investment. It may also be difficult to obtain reliable information about a bank loan or loan participation. Further, interests in bank loans and loan participations are not considered to be securities and, therefore, are not protected under the federal securities laws, including the Investment Company Act of 1940, as amended ("1940 Act").As part of transacting in bank loans the Fund may come into possession of material nonpublic information about a borrower as a result of its investment. Because of prohibitions on trading while in possession of such information, the Fund may be unable to invest or transact in the publicly traded securities of that borrower when it would otherwise be advantageous to do so.

Many loans are relatively illiquid or subject to restrictions on resale and may be difficult to value, which will have an adverse impact on the Fund's ability to dispose of particular bank loans or loan participations when necessary to meet redemption requests or liquidity needs, or to respond to a specific economic event, such as deterioration in the creditworthiness of the borrower. Bank loans may also be subject to extension risk and prepayment risk.

Collateralized Loan Obligations Risk. The Fund is subject to asset manager, legal and regulatory, limited recourse, liquidity, redemption, and reinvestment risks as a result of the structure of CLOs in which the Fund may invest. A CLO's performance is linked to the expertise of the CLO manager and its ability to manage the CLO portfolio. Changes in the regulation of CLOs may adversely affect the value of the CLO investments held by the Fund and the ability of the Fund to execute its investment strategy. CLO debt is payable solely from the proceeds of the CLO's underlying assets and, therefore, if the income from the underlying loans is insufficient to make payments on the CLO debt, no other assets will be available for payment. CLO debt securities may be subject to redemption and the timing of redemptions may adversely affect the returns on CLO debt. The CLO manager may not find suitable assets in which to invest and the CLO manager's opportunities to invest may be limited.

Mortgage-Backed and Asset-Backed Securities Risk. Mortgage-backed and asset-backed securities represent interests in "pools" of mortgages or other assets, including consumer and commercial loans or receivables held in trust. Mortgage-backed securities are subject to "prepayment risk" (the risk that borrowers will repay a loan more quickly in periods of falling interest rates) and "extension risk" (the risk that borrowers will repay a loan more slowly in periods of rising interest rates). If the Fund invests in mortgage-backed or asset-backed securities that are subordinated to other interests in the same pool, the Fund may only receive payments after the pool's obligations to other investors have been satisfied. An unexpectedly high rate of defaults on the assets held by a pool may limit substantially the pool's ability to make payments of principal or interest to the Fund, reducing the values of those securities or in some cases rendering them worthless. The Fund's investments in other asset-backed securities are subject to risks similar to those associated with mortgage-backed securities, as well as additional risks associated with the nature of the assets and the servicing of those assets.

Sector Focus Risk. The Fund may invest a larger portion of its assets in one or more sectors than many other mutual funds, and thus will be more susceptible to negative events affecting those sectors.

Call Risk. Call risk is the risk that an issuer, especially during a period of falling interest rates, may redeem a security by repaying it early, which may reduce the Fund's income if the proceeds are reinvested at lower interest rates.

Foreign Investment Risk. The prices of foreign securities may be more volatile than the prices of securities of U.S. issuers because of economic and social conditions abroad, political developments, and changes in the regulatory environments of foreign countries. Changes in exchange rates and interest rates, and the imposition of sanctions, confiscations, trade restrictions (including tariffs) and other government restrictions by the United States and/or other governments may adversely affect the values of the Fund's foreign investments. Foreign companies are generally subject to different legal and accounting standards than U.S. companies, and foreign financial intermediaries may be subject to less supervision and regulation than U.S. financial firms.

Management and Strategy Risk. The value of your investment depends on the judgment of the Sub-advisor about the quality, relative yield, value or market trends affecting a particular security, industry, sector or region, which may prove to be incorrect.

U.S. Government Securities Risk. Treasury obligations may differ in their interest rates, maturities, times of issuance and other characteristics. Obligations of U.S. government agencies and authorities are supported by varying degrees of credit but generally are not backed by the full faith and credit of the U.S. government. No assurance can be given that the U.S. government will provide financial support to its agencies and authorities if it is not obligated by law to do so.

Sovereign Debt Risk. Sovereign debt instruments are subject to the risk that a governmental entity may delay or refuse to pay interest or repay principal on its sovereign debt due, for example, to cash flow problems, insufficient foreign currency reserves, political considerations, the relative size of the governmental entity's debt position in relation to the economy or the failure to put in place economic reforms required by the International Monetary Fund or other multilateral agencies.

Emerging Markets Risk. Many of the risks with respect to foreign investments are more pronounced for investments in issuers in developing or emerging market countries. Emerging market countries tend to have more government exchange controls, more volatile interest and currency exchange rates, less market regulation, and less developed and less stable economic, political and legal systems than those of more developed countries. There may be less publicly available and reliable information about issuers in emerging markets than is available about issuers in more developed markets. In addition, emerging market countries may experience high levels of inflation and may have less liquid securities markets and less efficient trading and settlement systems.

Municipal Bond Risk. Interest rates on tax-exempt municipal bonds are generally lower than taxable bonds, and the return on investment in the Fund may be lower than an investment in another fund that does not invest in tax-exempt municipal obligations. Changes or proposed changes in federal tax laws could impact the value of the debt securities of municipal issuers that the Fund may purchase. Also, the failure or possible failure of such debt issuances to qualify for tax-exempt treatment may cause the prices of such municipal securities to decline, possibly adversely affecting the value of the Fund's portfolio, and such a failure could also result in additional taxable income to the Fund and its shareholders. The value of municipal securities can also be adversely affected by changes in the financial condition of one or more individual municipal issuers or credit enhancement providers for municipal issuers, regulatory and political developments, legislative actions, and by uncertainties and public perceptions concerning these and other factors. Financial difficulties impacting certain municipal issuers could result in an increasing number of defaults on obligations by municipal issuers.

Recent Market Events. Periods of market volatility may occur in response to market events, public health emergencies, natural disasters or climate events, and other economic, political, and global macro factors. For example, in recent years the large expansion of government deficits and debt as a result of government actions to mitigate the effects of the COVID-19 pandemic and inflation have resulted in extreme volatility in the global economy and in global financial markets. In addition, military conflicts and wars, such as Russia's invasion of Ukraine and the war among Israel, Hamas and other militant groups in the Middle East, have increased tensions in Europe and the Middle East and have caused and could continue to cause market disruptions in the regions and globally. These and other similar events could be prolonged and could adversely affect the value and liquidity of the Fund's investments, impair the Fund's ability to satisfy redemption requests, and negatively impact the Fund's performance.

Cybersecurity Risk. Cybersecurity incidents may allow an unauthorized party to gain access to Fund assets, customer data (including private shareholder information), or proprietary information, or cause the Fund, the Advisor, the Sub-Advisor, and/or other service providers (including custodians, sub-custodians, transfer agents and financial intermediaries) to suffer data breaches, data corruption or loss of operational functionality. In an extreme case, a shareholder's ability to exchange or redeem Fund shares may be affected. Issuers of securities in which the Fund invests are also subject to cybersecurity risks, and the value of those securities could decline if the issuers experience cybersecurity incidents.

Derivatives Risk. Derivatives include instruments and contracts that are based on and valued in relation to one or more underlying securities, financial benchmarks, indices, or other reference obligations or measures of value. Major types of derivatives include futures, options, swaps and forward contracts. Using derivatives exposes the Fund to additional or heightened risks, including leverage risk, liquidity risk, valuation risk, market risk, counterparty risk, and credit risk. Derivatives transactions can be highly illiquid and difficult to unwind or value, they can increase Fund volatility, and changes in the value of a derivative held by the Fund may not correlate with the value of the underlying instrument or the Fund's other investments. Many of the risks applicable to trading the instruments underlying derivatives are also applicable to derivatives trading. However, derivatives are subject to additional risks such as operational risk, including settlement issues, and legal risk, including that underlying documentation is incomplete or ambiguous. For derivatives that are required to be cleared by a regulated clearinghouse, other risks may arise from the Fund's relationship with a brokerage firm through which it submits derivatives trades for clearing, including in some cases from other clearing customers of the brokerage firm.

Futures and Options Risk. Futures and options may be more volatile than direct investments in the securities underlying the futures and options, may not exactly correlate to the underlying securities, may involve additional costs, and may be considered illiquid. Futures and options may also involve a small initial investment relative to the risk assumed, which could result in losses greater than if such instruments had not been used. Futures and options are also subject to counterparty risk (e.g., the risk that the other party to the transaction defaults on its obligation).

Swaps Risk. A swap is a two-party contract that generally obligates the parties to exchange payments based upon a specified reference security, index or index component. Swaps can involve greater risks than direct investment in securities or other similar instruments, because swaps may be leveraged and are subject to counterparty risk (e.g., the risk that the other party to the transaction defaults on its obligations), credit risk and valuation risk (i.e., swaps may be difficult to value). Swaps may also be considered illiquid. It may not be possible for the Fund to liquidate a swap position at an advantageous time or price, which may result in significant losses.

LIBOR Risk. The London Interbank Offered Rate ("LIBOR") was a leading benchmark or reference rate for various commercial and financial contracts, including corporate and municipal bonds, bank loans, asset-backed and mortgage-related securities, interest rate swaps and other derivatives. On July 27, 2017, the United Kingdom's Financial Conduct Authority announced the gradual phase out of the LIBOR rate, with nearly all LIBOR rate

publications having ceased as of June 30, 2023 (some LIBOR rates continue to be published, but only on a temporary and synthetic basis). Alternatives to LIBOR have been established and others may be developed. The transition to a new reference rate may result in (i) increased volatility or illiquidity in markets for instruments or contracts that previously relied on or still rely on LIBOR; (ii) a reduction in the value of certain instruments or contracts held by the Fund; (iii) reduced effectiveness of related Fund transactions, such as hedging; (iv) additional tax, accounting and regulatory risks; or (v) costs incurred in connection with closing out positions and entering into new trades. Any pricing adjustments to the Fund's investments resulting from a substitute reference rate may also adversely affect the Fund's performance and/or net asset value per share ("NAV").

Performance

The bar chart and table below provide an indication of the risks of investing in the Fund by showing changes in the Fund's performance from year to year for Class I shares and by showing how the average annual total returns of each class of the Fund compare with the average annual total returns of the Bloomberg Aggregate Bond Index and the Bloomberg 1-3 Year U.S. Government/Credit Index. The Bloomberg Aggregate Bond Index has been included as the primary broad-based securities market index in order to satisfy a change in regulatory requirements. The Fund also compares its performance with the returns of Bloomberg 1-3 Year U.S. Government/Credit Index, which the Advisor believes is a better performance benchmark for comparison to the Fund's performance in light of the Fund's investment strategies. Performance for classes other than those shown may vary from the performance shown to the extent the expenses for those classes differ. Updated performance information is available at the Fund's website, www.aamlive.com/publicsite/mutual-funds or by calling the Fund at 1-888-966-9661. The Fund's past performance, before and after taxes, is not necessarily an indication of how the Fund will perform in the future. Sales loads are not reflected in the bar chart, and if those charges were included, returns would be less than shown.

Calendar-Year Total Return (before taxes) for Class I Shares
For each calendar year at NAV

The year-to-date return as of September 30, 2024, was 5.19%.

*After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor's tax situation and may differ from those shown. After - tax returns shown are not relevant to investors who hold their Fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. After-tax returns are shown for Class I Shares only and after-tax returns for classes other than Class I will vary from returns shown for Class I.

Investment Advisor

Advisors Asset Management, Inc. (the "Advisor" or "AAM").

Sub-Advisor

Hartford Investment Management Company (the "Sub-Advisor" or "HIMCO").

Portfolio Managers

The portfolio management team is comprised of Robert Crusha, CFA, Senior Managing Director and Senior Portfolio Manager, and Shannon Carbray, CFA, Senior Director and Portfolio Manager. The portfolio managers have been jointly and primarily responsible for the day-to-day management of the Fund's portfolio since its inception on June 30, 2014.

Purchase and Sale of Fund Shares

To purchase shares of the Fund, you must invest at least the minimum amount.

Fund shares are redeemable on any business day the New York Stock Exchange (the "NYSE") is open for business, by written request or by telephone.

Tax Information

The Fund's distributions are generally taxable, and will ordinarily be taxed as ordinary income, qualified dividend income or capital gains, unless you are investing through a tax-advantaged arrangement, such as a 401(k) plan or an individual retirement account. Shareholders investing through such tax-advantaged arrangements may be taxed later upon withdrawal of monies from those arrangements.

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.