Eaton Vance Parametric Option Absolute Return Strategy Fund

Fund Summaries

Eaton Vance Parametric Option Absolute Return Strategy Fund

Investment Objective

The Fund’s investment objective is total return.

Fees and Expenses of the Fund

This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund. You may qualify for a reduced sales charge if you invest, or agree to invest over a 13-month period, at least $50,000 in Eaton Vance Funds. More information about these and other discounts is available from your financial intermediary and in Sales Charges beginning on page 25 of this Prospectus and page 21 of the Fund’s Statement of Additional Information.

Shareholder Fees (fees paid directly from your investment)

Shareholder Fees Eaton Vance Parametric Option Absolute Return Strategy Fund	Class A	Class C	Class I
Shareholder Fees Column [Text]	Class A	Class C	Class I
Maximum Sales Charge (Load) (as a percentage of offering price)	4.75%	none	none
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of net asset value at purchase or redemption)	none	1.00%	none

Annual Fund Operating Expenses		Eaton Vance Parametric Option Absolute Return Strategy Fund	Eaton Vance Parametric Option Absolute Return Strategy Fund Class A	Eaton Vance Parametric Option Absolute Return Strategy Fund Class C	Eaton Vance Parametric Option Absolute Return Strategy Fund Class I
Operating Expenses Caption [Text]		Annual Fund Operating Expenses (expenses you pay each year as a percentage of the value of your investment)
Operating Expenses Column [Text]			Class A	Class C	Class I
Management Fees			1.10%	1.10%	1.10%
Distribution and Service (12b-1) Fees			0.25%	1.00%
Other Expenses			0.45%	0.45%	0.45%
Total Annual Fund Operating Expenses			1.80%	2.55%	1.55%
Expense Reimbursement	[1]		(0.25%)	(0.25%)	(0.25%)
Total Annual Fund Operating Expenses After Expense Reimbursement			1.55%	2.30%	1.30%

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 and that the operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expenses with Redemption

Expense Example Eaton Vance Parametric Option Absolute Return Strategy Fund (USD $)	Expense Example, By Year, Column [Text]	1 Year	3 Years	5 Years	10 Years
Class A	Class A shares	625	991	1,381	2,471
Class C	Class C shares	333	770	1,333	2,867
Class I	Class I shares	132	465	821	1,824

Expenses without Redemption

Expense Example, No Redemption Eaton Vance Parametric Option Absolute Return Strategy Fund (USD $)	Expense Example, No Redemption, By Year, Column [Text]	1 Year	3 Years	5 Years	10 Years
Class A	Class A shares	625	991	1,381	2,471
Class C	Class C shares	233	770	1,333	2,867
Class I	Class I shares	132	465	821	1,824

Portfolio Turnover

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 103% of the average value of its portfolio.

Principal Investment Strategies

The Fund pursues its investment objective principally by writing a series of call and put option spread combinations on the S&P 500 Composite Stock Price Index (“S&P 500 Index”), a broad-based U.S. stock market index, and/or another proxy for the S&P 500 Index (such as the SPDR Trust Series I units (“SPDRs”)). The Fund’s option strategy employs a systematic, rules-based program that seeks to take advantage of the general imbalance of natural buyers of stock index options over natural sellers, which is reflected in the customary excess of option price-implied volatilities over observed market volatilities. The Fund seeks to mitigate risk by selling option “spreads,” rather than stand-alone options, by staggering roll dates across the option position portfolio, and by utilizing exchange-traded options guaranteed for settlement by the Options Clearing Corporation, a market clearinghouse.

The Fund will generally write call spreads and put spreads that are “out of the money”. That is, the exercise price of the call options sold generally will be above the current level of the index when written and the exercise price of the call options bought will be above the exercise price of the call options sold. The exercise price of put options sold generally will be below the current level of the index when written and the exercise price of the put options bought will be below the exercise price of put options sold.

The option program is intended to be substantially non-directional and to provide returns that are substantially uncorrelated to the returns of the S&P 500 Index. In implementing its strategy, the Fund generally intends to enter into written call and put option spread positions that primarily have a maturity of approximately four weeks, and to stagger the timing of its spread originations and expirations through each four-week period. For each option spread combination, the Fund intends to sell call spreads and put spreads on the S&P 500 Index with substantially equivalent notional values and identical expiration dates. The Fund will determine the number and composition of the call and put option spreads in each combination based largely on the market exposures and maximum net loss potential of such positions. Under normal circumstances, the Fund intends to limit its maximum option loss potential realizable for each call and put spread combination over its roll cycle to not more than 10% of the associated net asset value of the Fund, based on observable market inputs at the time the option spread combination is entered into and determined without consideration of net premiums received.

The Fund’s option strategy will be implemented as an overlay to a portfolio of short-term, high-grade income securities. A significant portion of this portfolio will be subject to the option strategy overlay. Short-term instruments are generally those with effective maturities of three years or less. High-grade instruments are rated A or higher by a rating agency or deemed to be of comparable quality by the investment adviser. The Fund expects to maintain a dollar-weighted average effective maturity of one year or less.

The Fund’s income securities investments are expected to consist primarily of U.S. dollar-denominated instruments of domestic and foreign issuers, including U.S. Government securities, commercial paper and other short-term, high-grade obligations issued by banks and corporations. Investments also may include other short-term, high-grade obligations including certificates of deposit, bankers’ acceptances and other short-term securities issued by domestic or foreign banks or their subsidiaries or branches, as well as high-grade mortgage-backed securities, commercial mortgage-backed securities and asset-backed securities. The Fund may invest in repurchase and reverse repurchase agreements and in variable or floating-rate securities, some of which provide for periodic recovery of principal on demand investments, and may purchase securities on a when-issued basis and for future delivery by means of “forward commitments.”

The Fund employs an absolute return investment approach. Absolute return strategies benchmark their performance primarily against short-term cash instruments, adjusting to compensate for the amount of investment risk assumed. Relative return strategies, by contrast, seek to outperform a designated stock, bond or other market index, and measure their performance primarily in relation to such benchmark. Over the long term, the investment performance of absolute return strategies would typically be expected to be substantially independent of movements in the stock and bond market.

Principal Risks

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 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.

The success of put and call spread transactions on the S&P 500 Index and/or a proxy for the S&P 500 Index will be determined 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 premium received, a loss will result. The risk of selling put options in a spread transaction is mitigated by the purchase of offsetting options at a lower exercise price, thereby capping the maximum loss potential.

Derivatives Risk. The use of derivatives can lead to losses because of adverse movements in the price or value of the asset, index, rate or instrument underlying a derivative, due to failure of a counterparty or due to tax or regulatory constraints. Derivatives may create economic leverage in the Fund, which magnifies the Fund’s exposure to the underlying investment. 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. When derivatives are used to gain or limit exposure to a particular market or market segment, their performance may not correlate as expected to the performance of such market thereby causing the Fund to fail to achieve its original purpose for using such derivatives. The 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. Derivative instruments 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 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 the return of collateral or other assets held by the counterparty. The loss on derivative transactions may substantially exceed the initial investment.

Debt Market Risk. Economic and other events (whether real or perceived) can reduce the demand for investments held by the Fund, which may reduce their market prices and cause the value of Fund shares to fall. The frequency and magnitude of such changes cannot be predicted. Certain securities and other investments held by the Fund can experience downturns in trading activity and, at such times, the supply of such instruments in the market may exceed the demand. At other times, the demand for such instruments may exceed the supply in the market. An imbalance in supply and demand in the market may result in valuation uncertainties and greater volatility, less liquidity, wider trading spreads and a lack of price transparency in the market. No active trading market may exist for certain investments, which may impair the ability of the Fund to sell or to realize the full value of such investments in the event of the need to liquidate such assets. Adverse market conditions may impair the liquidity of some actively traded investments.

Interest Rate Risk. As interest rates rise, the value of certain income securities is likely to decline. Conversely, when interest rates decline, the value of such securities is likely to rise. Securities with longer maturities are more sensitive to changes in interest rates than those with shorter maturities, making them more volatile. A rising interest rate environment may extend the average life of mortgages or other asset-backed receivables underlying mortgage-backed or asset-backed securities. This extension increases the risk of depreciation due to future increases in market interest rates. In a declining interest rate environment, prepayment of callable income investments may increase. In such circumstances, the Fund may have to reinvest the prepayment proceeds at lower yields.

Credit Risk. Investments in debt obligations 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 a debt obligation also may decline because of concerns about the issuer’s ability to make principal and interest payments. In addition, the credit ratings of income securities may be lowered if the financial condition of the party obligated to make payments with respect to such instruments changes. Credit ratings assigned by rating agencies are based on a number of factors and do not necessarily reflect the issuer’s current financial condition or the volatility or liquidity of the security. In the event of bankruptcy of the issuer of income securities, 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. This may increase the Fund’s operating expenses and adversely affect net asset value.

Risk of U.S. Government-Sponsored Agencies. Although certain U.S. Government-sponsored agencies (such as the Federal Home Loan Mortgage Corporation and Fannie Mae) may be chartered or sponsored by acts of Congress, their securities are neither issued nor guaranteed by the U.S. Treasury.

Foreign and Emerging Market Investment Risk. Because the Fund may invest a portion of its assets in foreign instruments, the value of Fund shares can be adversely affected by changes in currency exchange rates and political, economic and market developments abroad. In emerging or less developed countries, these risks can be more significant. Investment markets in emerging market countries are typically substantially smaller, less liquid and more volatile than the major markets in developed countries. As a result, Fund share values may be more volatile than if the Fund invested only in developed markets. Emerging market countries may have relatively unstable governments and economies. Emerging market investments often are subject to speculative trading, which typically contributes to volatility. Trading in foreign and emerging 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. The value of investments denominated in foreign currencies can be adversely affected by changes in foreign currency exchange rates.

Risks of Repurchase Agreements and Reverse Repurchase Agreements. In the event of the insolvency of the counterparty to a repurchase agreement or reverse repurchase agreement, recovery of the repurchase price owed to the Fund or, in the case of a reverse repurchase agreement, the securities sold by the Fund, may be delayed. In a repurchase agreement, such an insolvency may result in a loss to the extent that the value of the purchased securities decreases during the delay. In a reverse repurchase agreement, the counterparty’s insolvency may result in a loss equal to the amount by which the value of the securities sold by the Fund exceeds the repurchase price payable by the Fund; if the value of the purchased securities increases during such a delay, that loss may also be increased. When the Fund enters into a reverse repurchase agreement, any fluctuations in the market value of either the securities transferred to another party or the securities in which the proceeds may be invested would affect the market value of the Fund’s assets. As a result, such transactions may increase fluctuations in the net asset value of the Fund’s shares. Because reverse repurchase agreements may be considered to be the practical equivalent of borrowing funds, they constitute a form of leverage. If the Fund reinvests the proceeds of a reverse repurchase agreement at a rate lower than the cost of the agreement, entering into the agreement will lower the Fund’s yield.

Risk of Leveraged Transactions. Certain Fund transactions may give rise to a form of leverage. Such transactions may include, among others, reverse repurchase agreements, dollar rolls, borrowing, loans of portfolio securities and the use of when-issued, delayed delivery or forward commitment transactions, short sales and certain derivative transactions. The Fund is required to segregate liquid assets or otherwise cover the Fund’s obligation created by a transaction that may give rise to leverage. The use of leverage may cause the Fund to liquidate portfolio positions when it may not be advantageous to do so to satisfy its obligations or to meet segregation requirements. Leverage may cause the Fund 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 loss on leveraged transactions may substantially exceed the initial investment.

Risks Associated with Active Management. The Fund is an actively managed portfolio and its success depends upon the investment skills and analytical abilities of the investment adviser to develop and effectively implement strategies to achieve the Fund’s investment objective. Subjective decisions made by the investment adviser may cause the Fund to incur losses or to miss profit opportunities on which it may otherwise have capitalized.

General Fund Investing Risks. The Fund is not a complete investment program and you may lose money by investing in the Fund. All investments carry a certain amount of risk and there is no guarantee that the Fund will be able to achieve its investment objective. Annual Fund Operating Expenses expressed as a percentage of the Fund’s average daily net assets may change as Fund assets increase and decrease, and Annual Fund Operating Expenses may differ in the future. Purchase and redemption activities by Fund shareholders may impact the management of the Fund and its ability to achieve its investment objective. Investors in the Fund should have a long-term investment perspective and be able to tolerate potentially sharp declines in value. 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, entity or person. Mutual funds, investment advisers, other market participants and many securities markets are subject to rules and regulations and the jurisdiction of one or more regulators. Changes to applicable rules and regulations could have an adverse affect on securities markets and market participants, as well as on the Fund’s ability to execute its investment strategy.

Performance

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 returns over time compare with those of a broad-based securities market index. The return in the bar chart is for Class I shares. Past performance (both before and after taxes) is no guarantee of future results. 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 period from December 31, 2010 to December 31, 2011, the highest quarterly total return for Class I was 3.34% for the quarter ended June 30, 2011, and the lowest quarterly return was -2.66% for the quarter ended September 30, 2011.

Average Annual Total Return as of December 31, 2011

Average Annual Total Returns Eaton Vance Parametric Option Absolute Return Strategy Fund	Label	Index No Deduction for Fees, Expenses, Taxes [Text]	One Year	Life of Fund
Return Before Taxes Class A	Class A Return Before Taxes		(1.06%)	(0.41%)
Return Before Taxes Class C	Class C Return Before Taxes		2.18%	2.83%
Return Before Taxes Class I	Class I Return Before Taxes		4.06%	3.78%
Return After Taxes on Distributions Class I	Class I Return After Taxes on Distributions		4.03%	3.74%
Return After Taxes on Distributions and the Sale of Class I Shares Class I	Class I Return After Taxes on Distributions and the Sale of Class I Shares		2.67%	3.21%
BofA Merrill Lynch 3-Month U.S. Treasury Bill Index	BofA Merrill Lynch 3-Month U.S. Treasury Bill Index	(reflects no deduction for fees, expenses or taxes)	0.10%	0.11%

These returns reflect the maximum sales charge for Class A (4.75%) and any applicable contingent deferred sales charge (“CDSC”) for Class C. Class A, Class C and Class I commenced operations on September 30, 2010. BofA Merrill Lynch^® indices not for redistribution or other uses; provided “as is”, without warranties, and with no liability. Eaton Vance has prepared this report, BofAML does not endorse it, or guarantee, review, or endorse Eaton Vance’s products. 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 I 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 the Sale of Fund Shares for a period may be greater than or equal to Return After Taxes on Distributions for the same period because of losses realized on the sale of Fund shares.

[1] The investment adviser, sub-adviser and administrator have agreed to reimburse the Fund's expenses to the extent that Total Annual Fund Operating Expenses exceed 1.55% for Class A shares, 2.30% for Class C shares and 1.30% for Class I shares. This expense reimbursement will continue through April 30, 2013. Any amendment to or a termination of this reimbursement would require written 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, interest expense, taxes or litigation expenses. Amounts reimbursed may be recouped by the investment adviser, sub-adviser and administrator during the Fund's current fiscal year to the extent actual expenses are less than the contractual expense cap during such year.