The Fund 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 Fund's portfolio turnover rate was 7% of the average value of its portfolio.

Expense Breakpoint Discounts

rr_ExpenseBreakpointDiscounts

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 this Prospectus. More information about these and other discounts is available from your financial intermediary and in Sales Charges beginning on page 31 of this Prospectus and page 23 of the Fund’s Statement of Additional Information.

Expense Example

rr_ExpenseExampleHeading

Example.

Strategy

rr_StrategyHeading

Principal Investment Strategies

Strategy Portfolio Concentration

rr_StrategyPortfolioConcentration

Under normal market conditions, the Fund invests at least 80% of its net assets (plus any borrowings for investment purposes) in equity securities of companies located in emerging market countries (the “80% Policy”). A company will be considered to be located in an emerging market country if it is domiciled in and tied economically to one or more emerging market countries and may include a company’s stock which is trading in the form of a depositary receipt. Emerging market countries are generally countries not considered to be developed market countries, and therefore not included in the MSCI World Index. The Fund intends to invest primarily in securities issued by companies located in countries included in the MSCI Emerging Markets Index or the MSCI Frontier Markets Index. The MSCI Emerging Markets Index is an unmanaged index of common stocks of issuers in emerging markets countries. The MSCI Frontier Markets Index is an unmanaged index of common stocks of issuers in countries that have less-developed economies and financial markets than more established emerging markets, and often have more restrictions on foreign stock ownership. Securities acquired by the Fund are typically listed on stock exchanges in emerging market countries, but also may include securities traded in markets outside these countries. The Fund may invest in securities issued by companies with a broad range of market capitalizations, including those of smaller, less seasoned companies. More than 25% of the Fund’s total assets may be denominated in any single currency. 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”). The Fund may also lend its securities.

Risk

rr_RiskTextBlock

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. Such risks may be greater in frontier markets.

Frontier Market Investment Risk. Frontier markets are among the smallest and least mature investment markets. Frontier market countries may have greater political or economic instability and may also be subject to trade barriers, adjustments in currency values and developing or changing securities laws and other regulations. Investments in frontier market countries generally are less liquid and subject to greater price volatility than investments in developed markets or emerging markets.

China Region Risk. Economies of countries in the China region differ from the U.S. economy in various ways, such as structure, general development, government involvement, wealth distribution, interest rates, rate of growth of gross national product, rate of inflation, capital reinvestment, resource self-sufficiency and balance of payments position. As export-driven economies, the economies of countries in the China region are affected by developments in the economies and governmental actions of their principal trading partners, such as the imposition of trading restrictions and tariffs. China’s governmental actions and the actions of other governments located in the region can have a significant effect on the economic conditions in the China region or a particular issuer or industry, which could adversely affect the value and liquidity of investments. For example, a government may restrict investment in companies or industries considered important to national interests, intervene in the financial markets, maintain strict currency controls, or impose repatriation restrictions. Significant portions of the Chinese securities markets may become rapidly illiquid, as Chinese issuers may suspend the trading of their equity securities. In addition, there is the potential of increased tariffs and restrictions (and threats thereof) on trade between the U.S. and China, concerns of which have been heightened by recent developments in relations between the U.S., other trading partners and China. An increase in tariffs or trade restrictions, or even the threat of such developments, could lead to a significant reduction in international trade, which could have a negative impact on China’s export industry, Chinese issuers, the liquidity or price of the Fund’s direct or indirect investments in China and, therefore, the Fund. The Fund’s investments in Chinese securities are also subject to additional risks associated with differing regulatory and audit requirements across the Chinese and U.S. securities markets. Although

China and certain other countries in the China region may be larger and/or more established than many emerging markets, markets in these countries carry the high levels of risk associated with emerging markets. Investments in China involve a risk of total loss due to government action or inaction or other adverse circumstances.

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.

Focused Investment Risk. To the extent the Fund has substantial investments in a relatively small number of securities or issuers, or a particular market, industry, group of industries, country, region, group of countries, asset class or sector, the Fund’s performance will be more susceptible to any single economic, market, political, or regulatory occurrence affecting those particular securities or issuers or that particular market, industry, group of industries, country, region, group of countries, assets class, or sector than a fund that invests more broadly.

Geographic Risk. Because the Fund may invest significantly in a particular geographic region or country, the value of Fund shares may be affected by events that adversely affect that region or country and may fluctuate more than that of a fund that invests more broadly.

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.

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.

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.

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.

Rules-Based Management Risks. The sub-adviser uses proprietary investment techniques and analyses in making investment decisions for the Fund, seeking to achieve its investment objective while minimizing exposure to security-specific risk. The strategy seeks to take advantage of certain quantitative and behavioral market characteristics identified by the sub-adviser, utilizing a rules-based process and systematic rebalancing. A systematic investment process is dependent on the sub-adviser’s skill in developing and maintaining that process. The Fund’s strategy has not been independently tested or validated, and there can be no assurance that it will achieve the desired results.

Securities Lending Risk. Securities lending involves the risk that the Fund may lose money because the borrower of the loaned securities fails to return the securities in a timely manner or at all. The Fund also may lose rights in the collateral if the borrower fails financially. The Fund could also lose money if the value of the collateral decreases or if the value of any investments made with cash collateral declines.

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 Narrative

rr_PerformanceNarrativeTextBlock

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. Effective April 29, 2022, the Fund’s Investor Class shares were redesignated as Class A shares and the Fund’s Institutional Class shares were redesignated as Class I shares. 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 for certain periods reflects the effects of expense reductions. Absent these reductions, performance for certain periods would have been lower. Updated Fund performance information can be obtained by visiting www.eatonvance.com.

Performance Availability Website Address

rr_PerformanceAvailabilityWebSiteAddress

www.eatonvance.com

Bar Chart Does Not Reflect Sales Loads

rr_BarChartDoesNotReflectSalesLoads

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.

Bar Chart Closing

rr_BarChartClosingTextBlock

For the ten years ended December 31, 2024, the highest quarterly total return for Class A was 20.49% for the quarter ended December 31, 2020 and the lowest quarterly return was -30.74% for the quarter ended March 31, 2020. The year-to-date total return through the end of the most recent calendar quarter (December 31, 2024 to March 31, 2025) was 2.86%

Performance Table One Class of after Tax Shown

rr_PerformanceTableOneClassOfAfterTaxShown

After-tax returns for other Classes of shares will vary from the after-tax returns presented for Class A shares.

Performance Table Closing

rr_PerformanceTableClosingTextBlock

These returns reflect the maximum sales charge for Class A (5.25%) and any applicable contingent deferred sales charge (“CDSC”) for Class C. On April 29, 2022, the Fund’s Investor Class shares were redesignated as Class A shares and the Fund’s Institutional Class shares were redesignated as Class I shares. Investor Class shares had previously been sold without a sales charge. 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. Investors cannot invest directly in an Index.

Source for MSCI Emerging Markets Index: MSCI. MSCI data may not be reproduced or used for any other purpose. MSCI provides no warranties, has not prepared or approved this data, and has no liability hereunder.

After-tax returns are calculated using the highest historical individual U.S. 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 After-tax returns are calculated using the highest historical individual U.S. 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. to shareholders who hold shares in tax-deferred accounts or to shares held by nontaxable 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.

Risk

rr_RiskTextBlock

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.

Prospectus [Line Items]

rr_ProspectusLineItems

Index No Deduction for Fees, Expenses, Taxes

rr_IndexNoDeductionForFeesExpensesTaxes

(reflects net dividends, which reflect the deduction of withholding taxes)

Five Years

rr_AverageAnnualReturnYear05

1.70%

Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

5.25%

Management Fees

rr_ManagementFeesOverAssets

1.00%

Other Expenses

rr_OtherExpensesOverAssets

0.41%

Expense Reimbursement(2)

rr_FeeWaiverOrReimbursementOverAssets

(0.17%)

^[2]

1 Year

rr_ExpenseExampleYear01

$ 669

5 Years

rr_ExpenseExampleYear05

1,365

1 Year

rr_ExpenseExampleNoRedemptionYear01

669

5 Years

rr_ExpenseExampleNoRedemptionYear05

1,365

2015

rr_AnnualReturn2015

(16.64%)

2017

rr_AnnualReturn2017

27.01%

2019

rr_AnnualReturn2019

12.31%

2021

rr_AnnualReturn2021

4.20%

2023

rr_AnnualReturn2023

9.44%

One Year

rr_AverageAnnualReturnYear01

(0.15%)

Ten Years

rr_AverageAnnualReturnYear10

1.74%

Prospectus [Line Items]

rr_ProspectusLineItems

Five Years

rr_AverageAnnualReturnYear05

0.33%

One Year

rr_AverageAnnualReturnYear01

0.20%

Ten Years

rr_AverageAnnualReturnYear10

1.55%

Prospectus [Line Items]

rr_ProspectusLineItems

Maximum Deferred Sales Charge (Load) (as a percentage of the lower of net asset value at time of purchase or redemption)

rr_MaximumDeferredSalesChargeOverOfferingPrice

1.00%

Distribution and Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

1.00%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

2.41%

Total Annual Fund Operating Expenses After Expense Reimbursement

rr_NetExpensesOverAssets

2.24%

3 Years

rr_ExpenseExampleYear03

735

10 Years

rr_ExpenseExampleYear10

2,547

3 Years

rr_ExpenseExampleNoRedemptionYear03

735

10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 2,547

Five Years

rr_AverageAnnualReturnYear05

1.05%

Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Management Fees

rr_ManagementFeesOverAssets

1.00%

Other Expenses

rr_OtherExpensesOverAssets

0.41%

Expense Reimbursement(2)

rr_FeeWaiverOrReimbursementOverAssets

(0.17%)

^[2]

1 Year

rr_ExpenseExampleYear01

$ 126

5 Years

rr_ExpenseExampleYear05

755

1 Year

rr_ExpenseExampleNoRedemptionYear01

126

5 Years

rr_ExpenseExampleNoRedemptionYear05

755

One Year

rr_AverageAnnualReturnYear01

5.62%

Ten Years

rr_AverageAnnualReturnYear10

2.54%

Prospectus [Line Items]

rr_ProspectusLineItems

Maximum Deferred Sales Charge (Load) (as a percentage of the lower of net asset value at time of purchase or redemption)

rr_MaximumDeferredSalesChargeOverOfferingPrice

none

Distribution and Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

none

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.34%

Total Annual Fund Operating Expenses After Expense Reimbursement

rr_NetExpensesOverAssets

1.17%

3 Years

rr_ExpenseExampleYear03

408

10 Years

rr_ExpenseExampleYear10

1,598

3 Years

rr_ExpenseExampleNoRedemptionYear03

408

10 Years

rr_ExpenseExampleNoRedemptionYear10

$ 1,598

Five Years

rr_AverageAnnualReturnYear05

2.15%

Risk/Return

rr_RiskReturnHeading

Parametric International Equity Fund

Objective, Primary

rr_ObjectivePrimaryTextBlock

The Fund's investment objective is to seek long-term capital appreciation.

Expense Narrative

rr_ExpenseNarrativeTextBlock

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 this Prospectus. More information about these and other discounts is available from your financial intermediary and in Sales Charges beginning on page 31 of this Prospectus and page 23 of the Fund’s Statement of Additional Information.

Operating Expenses Caption

rr_OperatingExpensesCaption

Annual Fund Operating Expenses (expenses you pay each year as a percentage of the value of your investment)

Portfolio Turnover

rr_PortfolioTurnoverHeading

Portfolio Turnover

Portfolio Turnover, Rate

rr_PortfolioTurnoverRate

19.00%

Expense Breakpoint, Minimum Investment Required

rr_ExpenseBreakpointMinimumInvestmentRequiredAmount

$ 50,000

Expense Example Narrative

rr_ExpenseExampleNarrativeTextBlock

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:

Strategy Narrative

rr_StrategyNarrativeTextBlock

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 equity securities (the “80% Policy”). The Fund invests primarily in companies domiciled in and tied economically to one or more countries represented in the MSCI Europe, Australasia, Far East Index (“MSCI EAFE Index”) and may include securities trading in the form of depositary receipts. The MSCI EAFE Index is an unmanaged index of approximately 700 companies. The Fund may invest in securities of companies with a broad range of market capitalizations, including those of smaller, less seasoned companies. The Fund may invest in publically-traded real estate investment trusts (“REITs”). The Fund intends to invest in not less than five different countries and more than 25% of the Fund’s total assets may be denominated in any single currency. 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 lend its securities.

The Fund seeks to employ a top-down, disciplined and systematic investment process that emphasizes broad exposure and diversification among developed markets outside of the United States, economic sectors and issuers. This rules-based strategy utilizes targeted allocation and systematic rebalancing to take advantage of certain quantitative and behavioral characteristics of developed markets identified by the portfolio managers. The investment process is periodically re-evaluated and may be adjusted to ensure that the process is consistent with the Fund’s investment objective and strategies. The portfolio managers select and allocate across countries based on factors such as market capitalization, volatility, correlation to other markets, liquidity, and perceived risk and potential for growth. The Fund maintains a bias to broad inclusion; that is the Fund intends to allocate its portfolio holdings to more developed markets outside of the United States rather than fewer developed markets. Relative to capitalization-weighted country indexes, the Fund’s individual country allocation targets seek to emphasize the less represented developed markets and attempt to reduce concentration risks relative to a capitalization-weighted index. The Fund’s country allocations are typically rebalanced to their target weights if they exceed a certain pre-determined overweight or fall below a certain pre-determined underweight. The frequency of rebalancing depends on the volatility and trading costs of the individual country. This is intended to reduce exposure to countries with strong relative performance and increasing exposure to countries which have underperformed. The Fund seeks to maintain exposure across key economic sectors. Relative to capitalization-weighted country indexes, the portfolio managers target weights to these sectors to emphasize the less represented sectors. The portfolio managers use a quantitative model to select individual securities as representatives of their countries and economic sectors. The model includes factors such as beta, or a stock’s historical sensitivity to movements in the global equity market, with the objective of reducing portfolio risk and maintaining broad diversification.

Risk

rr_RiskHeading

Principal Risks

Bar Chart and Performance Table

rr_BarChartAndPerformanceTableHeading

Performance

Performance Information Illustrates Variability of Returns

rr_PerformanceInformationIllustratesVariabilityOfReturns

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.

Performance Past Does Not Indicate Future

rr_PerformancePastDoesNotIndicateFuture

Past performance (both before and after taxes) is not necessarily an indication of how the Fund will perform in the future.

Annual Return Caption

rr_AnnualReturnCaption

Calendar year-by-year total return

Year to Date Return, Label

rr_YearToDateReturnLabel

The year-to-date total return through the end of the most recent calendar quarter (December 31, 2024 to March 31, 2025) was 8.11%.

Performance Table Uses Highest Federal Rate

rr_PerformanceTableUsesHighestFederalRate

After-tax returns are calculated using the highest historical individual U.S. 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.

Performance Table One Class of after Tax Shown

rr_PerformanceTableOneClassOfAfterTaxShown

After-tax returns for other Classes of shares will vary from the after-tax returns presented for Class A shares.

Performance Table Footnotes, Reason Performance Information for Class Different from Immediately Preceding Period

rr_PerformanceTableFootnotesReasonPerformanceInformationForClassDifferentFromImmediatelyPrecedingPeriod

The Class R and Class R6 performance shown above for the period prior to August 10, 2015 (commencement of operations of each class), is the performance of Class A shares and Class I shares, respectively, at net asset value without adjustment for any differences in the expenses of the classes. If adjusted for such differences returns would be lower.

Average Annual Return, Caption

rr_AverageAnnualReturnCaption

Average Annual Total Return as of December 31, 2024

Prospectus [Line Items]

rr_ProspectusLineItems

Risk

rr_RiskTextBlock

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.

Prospectus [Line Items]

rr_ProspectusLineItems

One Year

rr_AverageAnnualReturnYear01

3.82%

Ten Years

rr_AverageAnnualReturnYear10

5.19%

Prospectus [Line Items]

rr_ProspectusLineItems

Maximum Deferred Sales Charge (Load) (as a percentage of the lower of net asset value at time of purchase or redemption)

rr_MaximumDeferredSalesChargeOverOfferingPrice

none

^[3]

Distribution and Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

0.25%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.88%

Total Annual Fund Operating Expenses After Expense Reimbursement

rr_NetExpensesOverAssets

0.78%

3 Years

rr_ExpenseExampleYear03

781

10 Years

rr_ExpenseExampleYear10

$ 1,544

2016

rr_AnnualReturn2016

1.42%

2018

rr_AnnualReturn2018

(11.51%)

2020

rr_AnnualReturn2020

9.61%

2022

rr_AnnualReturn2022

(15.85%)

2024

rr_AnnualReturn2024

1.38%

Bar Chart, Year to Date Return

rr_BarChartYearToDateReturn

8.11%

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Dec. 31, 2022

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

lowest quarterly return

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(22.76%)

Five Years

rr_AverageAnnualReturnYear05

2.10%

One Year

rr_AverageAnnualReturnYear01

(5.34%)

Ten Years

rr_AverageAnnualReturnYear10

3.89%

Prospectus [Line Items]

rr_ProspectusLineItems

Five Years

rr_AverageAnnualReturnYear05

1.75%

Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Management Fees

rr_ManagementFeesOverAssets

0.40%

Other Expenses

rr_OtherExpensesOverAssets

0.23%

^[4]

Expense Reimbursement(2)

rr_FeeWaiverOrReimbursementOverAssets

(0.10%)

^[5]

1 Year

rr_ExpenseExampleYear01

$ 54

5 Years

rr_ExpenseExampleYear05

341

One Year

rr_AverageAnnualReturnYear01

1.74%

Ten Years

rr_AverageAnnualReturnYear10

5.26%

Prospectus [Line Items]

rr_ProspectusLineItems

Maximum Deferred Sales Charge (Load) (as a percentage of the lower of net asset value at time of purchase or redemption)

rr_MaximumDeferredSalesChargeOverOfferingPrice

none

Distribution and Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

0.50%

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

1.13%

Total Annual Fund Operating Expenses After Expense Reimbursement

rr_NetExpensesOverAssets

1.03%

3 Years

rr_ExpenseExampleYear03

349

10 Years

rr_ExpenseExampleYear10

$ 1,366

Five Years

rr_AverageAnnualReturnYear05

2.96%

Inception Date

rr_AverageAnnualReturnInceptionDate

Aug. 10, 2015

Prospectus [Line Items]

rr_ProspectusLineItems

Maximum Deferred Sales Charge (Load) (as a percentage of the lower of net asset value at time of purchase or redemption)

rr_MaximumDeferredSalesChargeOverOfferingPrice

none

Distribution and Service (12b-1) Fees

rr_DistributionAndService12b1FeesOverAssets

none

Total Annual Fund Operating Expenses

rr_ExpensesOverAssets

0.60%

Total Annual Fund Operating Expenses After Expense Reimbursement

rr_NetExpensesOverAssets

0.50%

3 Years

rr_ExpenseExampleYear03

182

10 Years

rr_ExpenseExampleYear10

$ 740

Five Years

rr_AverageAnnualReturnYear05

3.51%

Inception Date

rr_AverageAnnualReturnInceptionDate

Aug. 10, 2015

Prospectus [Line Items]

rr_ProspectusLineItems

Risk/Return

rr_RiskReturnHeading

Parametric Volatility Risk Premium - Defensive Fund

Objective, Primary

rr_ObjectivePrimaryTextBlock

The Fund's investment objective is total return.

Expense Narrative

rr_ExpenseNarrativeTextBlock

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.

Operating Expenses Caption

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Annual Fund Operating Expenses (expenses you pay each year as a percentage of the value of your investment)

Portfolio Turnover

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The Fund 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 Fund's portfolio turnover rate was 14% of the average value of its portfolio.

Expense Example

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Example.

Strategy

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Principal Investment Strategies

Strategy Portfolio Concentration

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The Fund pursues its objective by investing in a base portfolio that is generally comprised of an approximately equal mix of equity securities and money market instruments. The Fund writes (sells) call options on the S&P 500® Index, a broad-based U.S. stock market index, and/or a substitute for the S&P 500® Index (the “S&P 500® Index” or the “Index”) on substantially the full value of the Fund’s equity securities. The Fund also writes (sells) put options on the S&P 500® Index or a substitute for such Index on substantially the full value of the Fund’s money market instrument holdings.

Risk

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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. No active trading market may exist for certain investments held by the Fund, which may impair the ability of the Fund to sell or to realize the current valuation of such investments in the event of the need to liquidate such assets.

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.

Option Strategy Risk. The Fund’s option strategy seeks to take advantage of, and its effectiveness is dependent on, a general excess of option price-implied volatilities for the S&P 500® Index over realized index volatilities. This market observation is often attributed to an excess of natural buyers over natural sellers of S&P 500® Index options. There can be no assurance that this imbalance will apply in the future over specific periods or generally. It is possible that the imbalance could decrease or be eliminated by actions of investors, including the Fund, that employ strategies seeking to take advantage of the imbalance, which could have an adverse effect on the Fund’s ability to achieve its investment objective.

S&P 500® Index Risk. Calls and puts written by the Fund will be based on the S&P 500® Index or a substitute for the S&P 500® Index. In the case of the S&P 500® Index, returns realized on the Fund’s call and put positions over each roll cycle will be determined primarily by the performance of the S&P 500® Index. If the S&P 500® Index appreciates or depreciates sufficiently over the period to offset the net premium received, the Fund will incur a net loss. A substitute for the S&P 500® Index represents share interests in an exchange-traded fund that seeks to replicate the performance of the S&P 500® Index. The value of the index substitute is subject to change as the values of the component securities fluctuate. The performance of the index substitute may not exactly match the performance of the S&P 500® Index. Certain index substitute options do not qualify as “section 1256 contracts” and disposition of such index substitute options utilized will likely result in short-term or long-term capital gains or losses, depending on the holding period. An index substitute

reflects the underlying risks of the S&P 500® Index and index substitute options are subject to the same risks as S&P 500® Index options.

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.

Leverage Risk. Certain Fund transactions may give rise to leverage. Leverage can result from a non-cash exposure to an underlying reference instrument. Leverage can increase both the risk and return potential of the Fund. The use of leverage may cause the Fund to maintain liquid assets or liquidate portfolio positions when it may not be advantageous to do so to satisfy its obligations. Leverage may cause the Fund’s share price to be more volatile than if it had not been leveraged, as certain types of leverage may exaggerate the effect of any increase or decrease in the value of the Fund’s portfolio securities. The Fund may not be able to adjust its use of leverage rapidly enough to respond to interest rate volatility, inflation, and other changing market conditions. As a result, the Fund’s use of leverage may have a negative impact on the Fund’s performance from time to time. The loss on leveraged investments may substantially exceed the initial investment.

U.S. Treasury Securities. U.S. Treasury securities (“Treasury Securities”) are obligations of the U.S. Treasury that differ in their interest rates, maturities and times of issuance. Treasury Securities include any security or agreement collateralized or otherwise secured by Treasury Securities. As a result of their high credit quality and market liquidity, U.S. Treasury securities generally provide a lower current return than obligations of other issuers.

Money Market Instrument Risk. Money market instruments may be adversely affected by market and economic events, such as a sharp rise in prevailing short-term interest rates; adverse developments in the banking industry, which issues or guarantees many money market instruments; adverse economic, political or other developments affecting issuers of money market instruments; changes in the credit quality of issuers; and default by a counterparty.

Interest Rate Risk. In general, the value of income securities will fluctuate based on changes in interest rates. The value of these securities is likely to increase when interest rates fall and decline when interest rates rise. Duration measures the time-weighted expected cash flows of a fixed-income security, while maturity refers to the amount of time until a fixed-income security matures. Generally, securities with longer durations or maturities are more sensitive to changes in interest rates than securities with shorter durations or maturities, causing them to be more volatile. Conversely, fixed-income securities with shorter durations or maturities will be less volatile but may provide lower returns than fixed-income securities with longer durations or maturities. In a rising interest rate environment, the duration of income securities that have the ability to be prepaid or called by the issuer may be extended. In a declining interest rate environment, the proceeds from prepaid or maturing instruments may have to be reinvested at a lower interest rate.

Credit Risk. Investments in fixed income and other debt obligations (referred to below as “debt instruments”) are subject to the risk of non-payment of scheduled principal and interest. Changes in economic conditions or other circumstances may reduce the capacity of the party obligated to make principal and interest payments on such instruments and may lead to defaults. Such non-payments and defaults may reduce the value of Fund shares and income distributions. The value of debt instruments also may decline because of concerns about the issuer’s ability to make principal and interest payments. In addition, the credit ratings of debt instruments may be lowered if the financial condition of the party obligated to make payments with respect to such instruments deteriorates. In the event of bankruptcy of the issuer of a debt instrument, the Fund could experience delays or limitations with respect to its ability to realize the benefits of any collateral securing the instrument. In order to enforce its rights in the event of a default, bankruptcy or similar situation, the Fund may be required to retain legal or similar counsel, which may increase the Fund’s operating expenses and adversely affect net asset value.

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.

Tax Risk. Only options on certain designated qualified trading markets qualify for treatment as “section 1256 contracts,” on which capital gains and losses are generally treated as 60% long-term and 40% short-term, regardless of holding period. To implement its options program most effectively, the Fund may sell index options that do not qualify for treatment as “section 1256 contracts.” Gains or losses on index options not qualifying as “section 1256 contracts” under the Code would be realized upon disposition, lapse or settlement of the positions, and, generally, would be treated as short-term gains or losses. If positions held by the Fund were treated as “straddles” for federal income tax purposes, dividends on such positions would not constitute qualified dividend income subject to favorable income tax treatment. Gains or losses on positions in a straddle are subject to special (and generally disadvantageous) tax rules.

Securities Lending Risk. Securities lending involves the risk that the Fund may lose money because the borrower of the loaned securities fails to return the securities in a timely manner or at all. The Fund also may lose rights in the collateral if the borrower fails financially. The Fund could also lose money if the value of the collateral decreases or if the value of any investments made with cash collateral declines.

Rules-Based Management Risks. The sub-adviser uses proprietary investment techniques and analyses in making investment decisions for the Fund, seeking to achieve its investment objective while minimizing exposure to security-specific risk. The strategy seeks to take advantage of certain quantitative and behavioral market characteristics identified by the sub-adviser, utilizing a rules-based process and systematic rebalancing. A systematic investment process is dependent on the sub-adviser’s skill in developing and maintaining that process. The Fund’s strategy has not been independently tested or validated, and there can be no assurance that it will achieve the desired results.

Focused Investment Risk. To the extent the Fund has substantial investments in a relatively small number of securities or issuers, or a particular market, industry, group of industries, country, region, group of countries, asset class or sector, the Fund’s performance will be more susceptible to any single economic, market, political, or regulatory occurrence affecting those particular securities or issuers or that particular market, industry, group of industries, country, region, group of countries, assets class, or sector than a fund that invests more broadly.

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 Narrative

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The following bar chart and table provide some indication of the risks of investing in the Fund by showing how the Fund’s average annual total return compares with those of one or more indexes intended to measure broad market performance. The Fund’s primary benchmark index was changed from the Cboe S&P 500 BuyWrite Indexsm to the S&P 500® Index effective May 1, 2024 to comply with the regulation that requires the Fund’s primary benchmark to represent the overall applicable market. The additional index(es) in the table provide a means to compare the Fund’s average annual returns to a benchmark that the investment adviser believes is representative of the Fund’s investment universe. Effective April 29, 2022, the Fund’s Institutional Class shares were redesignated as Class I shares. 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.

Performance Availability Website Address

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www.eatonvance.com

Bar Chart Does Not Reflect Sales Loads

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The Fund’s performance reflects the effects of expense reductions. Absent these reductions, performance would have been lower.

Bar Chart Closing

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During the period from December 31, 2017 through December 31, 2024, the highest quarterly total return was 10.58% for the quarter ended June 30, 2020, and the lowest quarterly return was -16.08% for the quarter ended March 31, 2020. The year-to-date total return through the end of the most recent calendar quarter (December 31, 2024 to March 31, 2025) was -1.62%.

Performance Table Uses Highest Federal Rate

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After-tax returns are calculated using the highest historical individual U.S. 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.

Performance Table Explanation after Tax Higher

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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.

Average Annual Return, Caption

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Average Annual Total Return as of December 31, 2024

Prospectus [Line Items]

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Risk

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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.

Prospectus [Line Items]

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One Year

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25.02%

Life of Fund

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14.54%

Prospectus [Line Items]

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One Year

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