Summary Prospectus by Investment Company (Form 497K)

Investment Objective

The fund has an investment objective of capital appreciation.

Fees and Expenses

The tables below illustrate all 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 in Class A Shares if you and your family invest, or agree to invest in the future, at least $50,000 in Virtus Funds. More information on these and other discounts is available: (i) from your financial professional or other financial intermediary; (ii) under "Sales Charges" on page 114 of the fund's prospectus; (iii) with respect to purchase of shares through specific intermediaries, in Appendix A to the fund's prospectus, entitled "Intermediary Sales Charge Discounts and Waivers;" and (iv) under "Alternative Purchase Arrangements" on page 105 of the fund's statement of additional information ("SAI").

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(a)

The deferred sales charge is imposed on Class C Shares redeemed during the first year only.

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(b)

The fund's investment adviser has contractually agreed to limit the fund's total operating expenses (excluding certain expenses, such as front-end or contingent deferred sales charges, taxes, leverage and borrowing expenses (such as commitment, amendment and renewal expenses on credit or redemption facilities), interest, brokerage commissions, expenses incurred in connection with any merger or reorganization, unusual or infrequently occurring expenses (such as litigation), acquired fund fees and expenses, and dividend expenses, if any) so that such expenses do not exceed 0.83% for Class R6 Shares through January 31, 2023. Following the contractual period, the adviser may discontinue these expense reimbursement arrangements at any time. Under certain conditions, the adviser may recapture operating expenses reimbursed and/or fees waived under these arrangements for a period of three years following the date such waiver or reimbursement occurred, provided that the recapture does not cause the fund to exceed its expense limit in effect at the time of the waiver or reimbursement, and any in effect at the time of recapture, after repayment is taken into account.

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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 an investment of  $10,000 in the fund for the time periods indicated. It shows your costs if you sold your shares at the end of the period or continued to hold them. The example also assumes that your investment has a 5% return each year, that the fund's operating expenses remain the same and that the expense reimbursement arrangement remains in place for the contractual period. 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 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 17% of the average value of its portfolio.

Investments, Risks and Performance

Principal Investment Strategies

The fund invests in a select group of medium market capitalization growth companies believed by the subadviser to be undervalued relative to their future growth potential. The investment strategy emphasizes companies believed by the subadviser to have a sustainable competitive advantage, strong management and low financial risk, and to be able to grow over market cycles. Although the fund invests primarily in U.S. companies, it may invest in foreign securities and depositary receipts.

Under normal circumstances, the fund invests at least 80% of its assets in equity securities of medium market capitalization companies. As of the date of this Prospectus, the fund's subadviser considers medium market capitalization companies for this purpose to be those companies that, at the time of initial purchase, have market capitalizations generally within the range of companies included in the Russell Midcap® Index on a rolling three-year basis. On this basis, as of September 30, 2021, the total market capitalization range of companies included in the Russell Midcap® Index over the past three years was $72.5 million to $81.5 billion. Generally, the fund invests in approximately 25 to 50 securities at any given time.

Principal Risks

The fund may not achieve its objective(s), and it is not intended to be a complete investment program. The value of the fund's investments that supports your share value may decrease. If between the time you purchase shares and the time you sell shares the value of the fund's investments decreases, you will lose money. Investment values can decrease for a number of reasons. Conditions affecting the overall economy, specific industries or companies in which the fund invests can be worse than expected, and investments may fail to perform as the subadviser expects. As a result, the value of your shares may decrease. Purchase and redemption activities by fund shareholders may impact the management of the fund and its ability to achieve its investment objective(s). The principal risks of investing in the fund are identified below.

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Equity Securities Risk.  The value of the stocks held by the fund may be negatively affected by the financial market, industries in which the fund invests, or issuer-specific events. Focus on a particular style or in small or medium-sized companies may enhance that risk.

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Limited Number of Investments Risk.  Because the fund may have a limited number of securities, it may be more susceptible to factors adversely affecting its securities than a fund with a greater number of securities.

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Depositary Receipts Risk.  Investments in foreign companies through depositary receipts may expose the fund to the same risks as direct investments in securities of foreign issuers.

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Foreign Investing Risk.  Investing in foreign securities subjects the fund to additional risks such as increased volatility; currency fluctuations; less liquidity; less publicly available information about the foreign investment; and political, regulatory, economic, and market risk.

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Growth Stocks Risk.  The fund's investments in growth stocks may be more volatile than investments in other types of stocks, or may perform differently from the market as a whole and from other types of stocks.

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Market Volatility Risk.  The value of the securities in the fund may go up or down in response to the prospects of individual companies and/or general economic conditions. Price changes may be short- or long-term. Local, regional or global events such as war, acts of terrorism, the spread of infectious illness or other public health issue, recessions, or other events could have a significant impact on the fund and its investments, including hampering the ability of the fund's portfolio manager(s) to invest the fund's assets as intended.

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Medium Market Capitalization Companies Risk.  The fund's investments in medium market capitalization companies may increase the volatility and risk of loss to the fund, as compared with investments in larger, more established companies.

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Redemption Risk.  One or more large shareholders or groups of shareholders may redeem their holdings in the fund, resulting in an adverse impact on remaining shareholders in the fund by causing the fund to take actions it would not otherwise have taken.

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Performance Information

The bar chart and table below provide some indication of the potential risks of investing in the fund. The fund's past performance, before and after taxes, is not necessarily an indication of how the fund will perform in the future.

The bar chart shows changes in the fund's performance from year to year over a 10-year period.The table shows how the fund's average annual returns compare to those of a broad-based securities market index. Updated performance information is available at virtus.com or by calling 800-243-1574.

Calendar year total returns for Class I Shares

Returns do not reflect sales charges and would be lower if they did.

Average Annual Total Returns (for the periods ended 12/31/21)

Returns reflect deduction of maximum sales charges and full redemption at end of periods shown.

The Russell Midcap® Growth Index is a market capitalization-weighted index of medium-capitalization, growth-oriented stocks of U.S. companies. The index is calculated on a total-return basis with dividends reinvested. The index is unmanaged and not available for direct investment.

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. After-tax returns are shown only for Class I Shares; after-tax returns for other classes will vary. Actual after-tax returns depend on the investor's tax situation and may differ from those shown. After-tax returns are not relevant to investors who hold fund shares in tax-deferred accounts or to shares held by non-taxable entities.

Management

The fund's investment adviser is Virtus Investment Advisers, Inc. ("VIA").

The fund's subadviser is Kayne Anderson Rudnick Investment Management, LLC ("KAR"), an affiliate of VIA.

Portfolio Manager

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Chris Armbruster, CFA,  Research Analyst at KAR. Mr. Armbruster has served as a Portfolio Manager of the fund since January 2020.

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Doug Foreman, CFA,  Chief Investment Officer, Portfolio Manager and a member of the Executive Management Committee at KAR. Mr. Foreman has served as a Portfolio Manager of the fund since 2012.

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Purchase and Sale of Fund Shares

Minimum initial investments applicable to Class A and Class C Shares:

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$2,500, generally

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$100 for Individual Retirement Accounts (IRAs), systematic purchase or exchange accounts

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No minimum for defined contribution plans, asset-based fee programs, profit-sharing plans or employee benefit plans.

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Minimum additional investments applicable to Class A and Class C Shares:

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$100, generally

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No minimum for defined contribution plans, asset-based fee programs, profit-sharing plans or employee benefit plans.

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For Class I Shares, the minimum initial purchase is $100,000; there is no minimum for additional purchases.

Class R6 Shares are offered without a minimum initial investment to the following investors in plan level or omnibus accounts only (provided that they do not require or receive any compensation, administrative payments, sub-transfer

agency payments or service payments with respect to Class R6 Shares): (i) qualified retirement plans, including, but not limited to, 401(k) plans, 457 plans, employer sponsored 403(b) plans, and defined benefit plans; (ii) banks and trust companies; (iii) insurance companies; (iv) financial intermediaries utilizing such shares in fee-based investment advisory programs; (v) registered investment companies; and (vi) non-qualified deferred compensation plans. Other institutional investors may be permitted to purchase Class R6 Shares subject to the fund's determination of eligibility and may be subject to a $2,500,000 minimum initial investment requirement.

In general, you may buy or sell shares of the fund by mail or telephone on any business day. You also may buy and sell shares through a financial professional, broker-dealer or other financial intermediary.

Taxes

The fund's distributions are taxable to you as either ordinary income or capital gains, except when your investment is through a tax-deferred arrangement, such as a 401(k) plan or an individual retirement account. Such tax-deferred arrangements may be taxed later upon withdrawal of monies from those arrangements.

Payments to Broker-Dealers and Other Financial Intermediaries

If you purchase 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 financial professional to recommend the fund over another investment.

No compensation, administrative payments, sub-transfer agency payments or service payments are paid to brokers or other entities from fund assets or the Distributor's or an affiliate's resources on sales of or investments in Class R6 Shares. Class R6 Shares do not carry sales commissions or pay Rule 12b-1 fees, or make payments to brokers or other entities to assist in, or in connection with, the sale of the fund's shares.

Ask your financial professional or visit your financial intermediary's website for more information.