Summary Prospectus by Investment Company - Form 497K

Summary Prospectus dated May 1, 2024

Eaton Vance Stock Fund

Class / Ticker A / EAERX C / ECERX I / EIERX

This Summary Prospectus is designed to provide investors with key fund information in a clear and concise format. Before you invest, you may want to review the Fund's Prospectus and Statement of Additional Information, which contain more information about the Fund and its risks. The Fund's Prospectus and Statement of Additional Information, both dated May 1, 2024, as may be amended or supplemented, are incorporated by reference into this Summary Prospectus. For free paper or electronic copies of the Fund's Prospectus, Statement of Additional Information, annual and semi-annual shareholder reports, and other information about the Fund, go to http://www.eatonvance.com/funddocuments, email a request to [email protected], call 1-800-262-1122, or ask any financial advisor, bank, or broker-dealer who offers shares of the Fund. Unless otherwise noted, page number references refer to the current Prospectus for this Fund.

Investment Objective

The Fund's investment objective is to achieve long-term capital appreciation by investing in a diversified portfolio of equity securities.

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. Investors may also pay commissions or other fees to their financial intermediary, which are not reflected below. You may qualify for a reduced sales charge on purchases of Class A shares if you invest, or agree to invest over a 13-month period, at least $50,000 in Eaton Vance funds. Certain financial intermediaries also may offer variations in Fund sales charges to their customers as described in Appendix A - Financial Intermediary Sales Charge Variations in the Fund's Prospectus. More information about these and other discounts is available from your financial intermediary and in Sales Charges beginning on page 23 of the Fund's Prospectus and page 22 of the Fund's Statement of Additional Information.

Shareholder Fees (fees paid directly from your investment)	Class A	Class C	Class I
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	5.25%	None	None
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of net asset value at purchase or redemption)	None(1)	1.00%	None

(1)	Class A shares purchased at net asset value in amounts of $1 million or more are subject to a 1.00% contingent deferred sales charge if redeemed within 12 months of purchase.

Annual Fund Operating Expenses (expenses you pay each year as a percentage of the value of your investment)(1)	Class A	Class C	Class I
Management Fees	0.60%	0.60%	0.60%
Distribution and Service (12b-1) Fees	0.25%	1.00%	None
Other Expenses	0.26%	0.26%	0.26%
Total Annual Fund Operating Expenses	1.11%	1.86%	0.86%
Expense Reimbursement(2)	(0.13)%	(0.13)%	(0.13)%
Total Annual Fund Operating Expenses After Expense Reimbursement	0.98%	1.73%	0.73%

(1)	Expenses in the table above and the Example below reflect the expenses of the Fund and Stock Portfolio (the "Portfolio"), the Portfolio in which the Fund invests.

(2)

The investment adviser and administrator have agreed to reimburse the Fund's expenses to the extent that Total Annual Fund Operating Expenses exceed 0.98% for Class A shares, 1.73% for Class C shares and 0.73% for Class I shares. This expense reimbursement will continue through May 1, 2025. Any amendment to or termination of this reimbursement would require approval of the Board of Trustees. The expense reimbursement relates to ordinary operating expenses only and does not include expenses such as: brokerage commissions, acquired fund fees and expenses of unaffiliated funds, borrowing costs (including borrowing costs of any acquired funds), taxes or litigation expenses. Amounts reimbursed may be recouped by the investment adviser and administrator during the same fiscal year to the extent actual expenses are less than any contractual expense cap in place during such year. Pursuant to this arrangement, the investment adviser and administrator may recoup from the Fund any reimbursed expenses during the same fiscal year if such recoupment does not cause the Fund's Total Annual Operating Expenses after such recoupment to exceed (i) the expense limit in effect at the time of reimbursement, or (ii) the expense limit in effect at the time of recoupment.

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. The Example also assumes that your investment has a 5% return each year, that the operating expenses remain the same and that any 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:

	Expenses with Redemption	Expenses without Redemption
	1 Year	3 Years	5 Years	10 Years	1 Year	3 Years	5 Years	10 Years
Class A shares	$620	$847	$1,093	$1,795	$620	$847	$1,093	$1,795
Class C shares	$276	$572	$994	$1,973	$176	$572	$994	$1,973
Class I shares	$75	$261	$464	$1,049	$75	$261	$464	$1,049

Portfolio Turnover

The Portfolio pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" the 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 Portfolio's portfolio turnover rate was 44% of the average value of its portfolio.

Principal Investment Strategies

Under normal market conditions, the Fund invests at least 80% of its net assets (plus any borrowings for investment purposes) in a diversified portfolio of common stocks (the "80% Policy"). The Fund may invest in companies with a broad range of market capitalizations, including smaller companies. The Fund generally intends to maintain investments in all or substantially all of the market sectors represented in the S&P 500^® Index. Particular stocks owned will not mirror the S&P 500^® Index. The Fund may invest up to 25% of its total assets in foreign securities which may be issued by companies domiciled in developed or emerging market countries. As an alternative to holding foreign stocks directly, the Fund may invest in U.S. dollar-denominated securities of foreign companies that trade on U.S. exchanges or in the over-the-counter market (including depositary receipts, such as American Depositary Receipts, which are either sponsored or unsponsored, and Global Depositary Receipts, which evidence ownership in underlying foreign stocks). The Fund may invest in exchange-traded funds ("ETFs"), a type of pooled investment vehicle, in order to manage cash positions or seek exposure to certain markets or market sectors. The Fund may also invest in publicly traded real estate investment trusts ("REITs"). At times, the Fund's investments may be focused in one or more sectors.

The Fund may engage in derivative transactions to seek return, to hedge against fluctuations in securities prices or as a substitute for the purchase or sale of securities. The Fund expects to use derivatives principally when seeking to gain exposure to equity securities by writing put options or to generate income by writing covered call options or put options. The Fund may also enter into a combination of options transactions on individual securities. Permitted derivatives include: the purchase or sale of forward or futures contracts; options on futures contracts; exchange-traded and over-the-counter options; equity collars and equity swap agreements. Except as required by applicable regulation, there is no stated limit on the Fund's use of derivatives for such purposes.

The portfolio of securities is selected primarily on the basis of fundamental research. The portfolio manager utilizes the information provided by, and the expertise of, the investment adviser's research staff in making investment decisions. In selecting securities, the portfolio manager seeks companies that have sustainable earnings and cash flow, a strong and durable financial profile, secular and cyclical growth prospects, and the ability to maintain a competitive position within its industry. In addition, the portfolio manager employs a portfolio construction process that seeks to manage investment risk. This process includes the use of portfolio optimization tools (quantitative tools that help track the Fund's fundamental characteristics such as its volatility, valuation and growth rate) and risk management techniques to assist in portfolio construction and monitoring and maintaining issuer and industry diversification among portfolio holdings. The portfolio manager may sell a security when he believes it is fully valued, the fundamentals of a company deteriorate, or to pursue alternative investment options.

The Fund currently invests substantially all of its assets in the Portfolio, a separate registered investment company with substantially the same investment objective and policies as the Fund. References to the Fund's investments include investments held indirectly through the Portfolio in which the Fund invests.

Principal Risks

Market Risk. The value of investments held by the Fund may increase or decrease in response to social, economic, political, financial, public health crises or other disruptive events (whether real, expected or perceived) in the U.S. and global markets and include events such as war, natural disasters, epidemics and pandemics, terrorism, conflicts and social unrest. These events may negatively impact broad segments of businesses and populations and may exacerbate pre-existing risks to the Fund. The frequency and magnitude of resulting changes in the value of the Fund's investments cannot be predicted. Certain securities and other investments held by the Fund may experience increased volatility, illiquidity, or other potentially adverse effects in reaction to changing market conditions. Monetary and/or fiscal actions taken by U.S. or foreign governments to stimulate or stabilize the global economy may not be effective and could lead to high market volatility.

Equity Securities Risk. The value of equity securities and related instruments may decline in response to adverse changes in the economy or the economic outlook; deterioration in investor sentiment; interest rate, currency, and commodity price fluctuations; adverse geopolitical, social or environmental developments; issuer and sector-specific considerations; unexpected trading activity among retail investors; or other factors. Market conditions may affect certain types of stocks to a greater extent than other types of stocks. If the stock market declines in value, the value of the Fund's equity securities will also likely decline. Although prices can rebound, there is no assurance that values will return to previous levels.

Foreign Investment Risk. Foreign investments can be adversely affected by political, economic and market developments abroad, including the imposition of economic and other sanctions by the United States or another country against a particular country or countries, organizations, entities and/or individuals. There may be less publicly available information about foreign issuers because they may not be subject to reporting practices, requirements or regulations comparable to those to which United States companies are subject. Adverse changes in investment regulations, capital requirements or exchange controls could adversely affect the value of the Fund's investments. Foreign markets may be smaller, less liquid and more volatile than the major markets in the United States and, as a result, Fund share values may be more volatile. Trading in foreign markets typically involves higher expense than trading in the United States. The Fund may have difficulties enforcing its legal or contractual rights in a foreign country. Depositary receipts are subject to many of the risks associated with investing directly in foreign instruments, including the political and economic risks of the underlying issuer's country and, in the case of depositary receipts traded on foreign markets, currency risk.

Emerging Markets Investment Risk. Investment markets within emerging market countries are typically smaller, less liquid, less developed and more volatile than those in more developed markets like the United States, and may be focused in certain sectors. Emerging market securities often involve greater risks than developed market securities. The information available about an emerging market issuer may be less reliable than for comparable issuers in more developed capital markets.

Currency Risk. Exchange rates for currencies fluctuate daily. The value of foreign investments may be affected favorably or unfavorably by changes in currency exchange rates in relation to the U.S. dollar. Currency markets generally are not as regulated as securities markets and currency transactions are subject to settlement, custodial and other operational risks.

ETF Risk. ETFs are subject to the risks of investing in the underlying securities or other investments. ETF shares may trade at a premium or discount to net asset value and are subject to secondary market trading risks. In addition, the Fund will bear a pro rata portion of the operating expenses of an ETF in which it invests.

Derivatives Risk. The Fund's exposure to derivatives involves risks different from, or possibly greater than, the risks associated with investing directly in securities and other investments. The use of derivatives can lead to losses because of adverse movements in the price or value of the security, instrument, index, currency, commodity, economic indicator or event underlying a derivative ("reference instrument"), due to failure of a counterparty or due to tax or regulatory constraints. Derivatives may create leverage in the Fund, which represents a non-cash exposure to the underlying reference instrument. Leverage can increase both the risk and return potential of the Fund. Derivatives risk may be more significant when derivatives are used to enhance return or as a substitute for a cash investment position, rather than solely to hedge the risk of a position held by the Fund. Use of derivatives involves the exercise of specialized skill and judgment, and a transaction may be unsuccessful in whole or in part because of market behavior or unexpected events. Changes in the value of a derivative (including one used for hedging) may not correlate perfectly with the underlying reference instrument. Derivative instruments traded in over-the-counter markets may be difficult to value, may be illiquid, and may be subject to wide swings in valuation caused by changes in the value of the underlying reference instrument. If a derivative's counterparty is unable to honor its commitments, the value of Fund shares may decline and the Fund could experience delays in (or be unable to achieve) the return of collateral or other assets held by the counterparty. The loss on derivative transactions may substantially exceed the initial investment. A derivative investment also involves the risks relating to the reference instrument underlying the investment.

Smaller Company Risk. The stocks of smaller, less seasoned companies are generally subject to greater price fluctuations, limited liquidity, higher transaction costs and higher investment risk than the stocks of larger, more established companies. Such companies may have limited product lines, markets or financial resources, may be dependent on a limited management group, and may lack substantial capital reserves or an established performance record. There may be generally less publicly available information about such companies than for larger, more established companies. Stocks of these companies frequently have lower trading volumes making them more volatile and potentially less liquid and more difficult to value.

Sector Risk. Because the Fund may, under certain market conditions invest a significant portion of its assets in one or more sectors, the value of Fund shares may be affected by events that adversely affect a particular sector and may fluctuate more than that of a fund that invests more broadly.

Information Technology Sector Risk. The value of Fund shares may be particularly impacted by events that adversely affect the information technology sector, such as rapid changes in technology product cycles, product obsolescence, government regulation, and competition, and may fluctuate more than that of a fund that does not concentrate in companies in the technology sector.

Real Estate Risk. Real estate investments are subject to risks associated with owning real estate, including declines in real estate values, increases in property taxes, fluctuations in interest rates, limited availability of mortgage financing, decreases in revenues from underlying real estate assets, declines in occupancy rates, changes in government regulations affecting zoning, land use, and rents, environmental liabilities, and risks related to the management skill and creditworthiness of the issuer. Companies in the real estate industry may also be subject to liabilities under environmental and hazardous waste laws, among others. REITs must satisfy specific requirements for favorable tax treatment and can involve unique risks in addition to the risks generally affecting the real estate industry. Changes in underlying real estate values may have an exaggerated effect to the extent that investments are concentrated in particular geographic regions or property types.

Liquidity Risk. The Fund is exposed to liquidity risk when trading volume, lack of a market maker or trading partner, large position size, market conditions, or legal restrictions impair its ability to sell particular investments or to sell them at advantageous market prices. Consequently, the Fund may have to accept a lower price to sell an investment or continue to hold it or keep the position open, sell other investments to raise cash or abandon an investment opportunity, any of which could have a negative effect on the Fund's performance. These effects may be exacerbated during times of financial or political stress.

Investing in a Portfolio. The Fund invests its assets in the Portfolio. This enables the Fund to pool its assets with other investors that also invest in the same Portfolio, resulting in efficiencies in management and administration that can lower the Fund's costs and enhance shareholder returns. The ability of the Fund operating in a hub and spoke structure to meet its investment objective is directly related to the ability of the corresponding Portfolio to meet its objective. Contribution and withdrawal activities by other Portfolio investors may impact the management of the Portfolio and its ability to achieve its investment objective.

Risks Associated with Active Management. The success of the Fund's investment strategy depends on portfolio management's successful application of analytical skills and investment judgment. Active management involves subjective decisions and there is no guarantee that such decisions will produce the desired results or expected returns. The portfolio manager also uses quantitative portfolio optimization and risk management techniques in making investment decisions for the Fund. There can be no assurance that these techniques will achieve the desired results.

General Fund Investing Risks. The Fund is not a complete investment program and there is no guarantee that the Fund will achieve its investment objective. It is possible to lose money by investing in the Fund. The Fund is designed to be a long-term investment vehicle and is not suited for short-term trading. Investors in the Fund should have a long-term investment perspective and be able to tolerate potentially sharp declines in value. Purchase and redemption activities by Fund shareholders may impact the management of the Fund and its ability to achieve its investment objective(s). In addition, the redemption by one or more large shareholders or groups of shareholders of their holdings in the Fund could have an adverse impact on the remaining shareholders in the Fund. The Fund relies on various service providers, including the investment adviser and sub-adviser, if applicable, in its operations and is susceptible to operational, information security and related events (such as public health crises, cyber or hacking attacks) that may affect the service providers or the services that they provide to the Fund. An investment in the Fund is not a deposit in a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Performance

The following bar chart and table provide some indication of the risks of investing in the Fund by showing changes in the Fund's performance from year to year and how the Fund's average annual returns over time compare with those of a broad-based securities market index. The returns in the bar chart are for Class A shares and do not reflect a sales charge. If the sales charge was reflected, the returns would be lower. Past performance (both before and after taxes) is not necessarily an indication of how the Fund will perform in the future. The Fund's performance reflects the effects of expense reductions. Absent these reductions, performance would have been lower. Updated Fund performance information can be obtained by visiting www.eatonvance.com.

For the ten years ended December 31, 2023, the highest quarterly total return for Class A was 21.77% for the quarter ended June 30, 2020, and the lowest quarterly return was -19.47% for the quarter ended March 31, 2020.

Average Annual Total Return as of December 31, 2023	One Year	Five Years	Ten Years
Class A Return Before Taxes	17.51%	13.88%	10.45%
Class A Return After Taxes on Distributions	13.36%	11.69%	8.26%
Class A Return After Taxes on Distributions and Sale of Class A Shares	13.29%	11.19%	8.10%
Class C Return Before Taxes	22.13%	14.26%	10.39%
Class I Return Before Taxes	24.41%	15.41%	11.32%
S&P 500® Index (reflects no deductions for fees, expenses or taxes)	26.29%	15.68%	12.03%

These returns reflect the maximum current sales charge for Class A (5.25%) and any applicable contingent deferred sales charge ("CDSC") for Class C. Effective November 5, 2020, Class C shares automatically convert to Class A shares eight years after purchase. The average annual total returns listed for Class C reflect conversion to Class A shares after eight years. Prior to November 5, 2020, Class C shares automatically converted to Class A shares ten years after purchase.

S&P Dow Jones Indices are a product of S&P Dow Jones Indices LLC ("S&P DJI") and have been licensed for use. S&P^® and S&P 500^® are registered trademarks of S&P DJI; Dow Jones^® is a registered trademark of Dow Jones Trademark Holdings LLC ("Dow Jones"); S&P DJI, Dow Jones and their respective affiliates do not sponsor, endorse, sell or promote the Fund, will not have any liability with respect thereto and do not have any liability for any errors, omissions, or interruptions of the S&P Dow Jones Indices. Investors cannot invest directly in an Index.

After-tax returns are calculated using the highest historical individual federal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on a shareholder's tax situation and the actual characterization of distributions, and may differ from those shown. After-tax returns are not relevant to shareholders who hold shares in tax-deferred accounts or to shares held by non-taxable entities. After-tax returns for other Classes of shares will vary from the after-tax returns presented for Class A shares. Return After Taxes on Distributions for a period may be the same as Return Before Taxes for that period because no taxable distributions were made during that period. Also, Return After Taxes on Distributions and Sale of Fund Shares for a period may be greater than or equal to Return Before Taxes and/or Return After Taxes on Distributions for the same period because of losses realized on the sale of Fund shares.

Management

Investment Adviser. Eaton Vance Management ("Eaton Vance") serves as investment adviser to the Fund. Boston Management and Research ("BMR") serves as investment adviser to the Portfolio.

Portfolio Manager. Charles B. Gaffney, Managing Director of Morgan Stanley and Vice President of Eaton Vance and BMR, has managed the Portfolio and its predecessor fund since November 2007 and the Fund since March 1, 2021.

Purchase and Sale of Fund Shares

You may purchase, redeem or exchange Fund shares on any business day, which is any day the New York Stock Exchange is open for business. You may purchase, redeem or exchange Fund shares either through your financial intermediary or (except for purchases of Class C shares by accounts with no specified financial intermediary) directly from the Fund either by writing to the Fund, P.O. Box 534439, Pittsburgh, PA 15253-4439, or by calling 1-800-262-1122. The minimum initial purchase or exchange into the Fund is $1,000 for each Class (with the exception of Class I) and $1,000,000 for Class I (waived in certain circumstances). There is no minimum for subsequent investments.

Tax Information

If your shares are held in a taxable account, the Fund's distributions will be taxed to you as ordinary income and/or capital gains, unless you are exempt from taxation. If your shares are held in a tax-advantaged account, you will generally be taxed only upon withdrawals from the account.

Payments to Broker-Dealers and Other Financial Intermediaries

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

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© 2024 Eaton Vance Management

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