Strategy. MFS (Massachusetts Financial Services Company, the fund's investment adviser) normally invests the fund's assets across different asset classes, including an allocation to equity securities and an allocation to debt instruments and/or cash and cash equivalents. MFS allocates the fund's assets across these asset classes based on its assessment of individual securities and the risk/return potential of the asset classes. MFS expects the fund's exposure to the following asset classes to normally fall within the following ranges: Asset Class Range Equity Securities 50% - 90% Debt Instruments, Cash, and/or Cash Equivalents 10% - 50% While MFS may use derivatives for any investment purpose, to the extent MFS uses derivatives, MFS expects to use derivatives primarily to increase or decrease exposure to … Show more… MFS (Massachusetts Financial Services Company, the fund's investment adviser) normally invests the fund's assets across different asset classes, including an allocation to equity securities and an allocation to debt instruments and/or cash and cash equivalents. MFS allocates the fund's assets across these asset classes based on its assessment of individual securities and the risk/return potential of the asset classes. MFS expects the fund's exposure to the following asset classes to normally fall within the following ranges: Asset Class Range Equity Securities 50% - 90% Debt Instruments, Cash, and/or Cash Equivalents 10% - 50% While MFS may use derivatives for any investment purpose, to the extent MFS uses derivatives, MFS expects to use derivatives primarily to increase or decrease exposure to these asset classes, as alternatives to direct investments in these asset classes, or to seek to limit the fund's exposure to certain extreme market events. Derivatives include futures, forward contracts, options, and swaps. The funds investment in and exposure to the asset classes identified above may vary significantly from time to time and may fall outside of the stated ranges. MFS may invest in or expose the fund to any of these asset classes without limit based on its assessment of the relative attractiveness of the asset class. Equity securities include common stocks, depositary receipts, and other securities that represent an ownership interest (or right to acquire an ownership interest) in a company or other issuer. In selecting equity investments for the fund, MFS is not constrained by any particular investment style. MFS may invest the funds assets in the stocks of companies it believes to have above average earnings growth potential compared to other companies (growth companies), in the stocks of companies it believes are undervalued compared to their perceived worth (value companies), or in a combination of growth and value companies. While MFS may invest the equity portion of the funds assets in securities of companies of any size, MFS primarily invests in securities of companies with large capitalizations. Debt instruments include corporate bonds, U.S. Government securities, foreign government securities, securitized instruments (including mortgage-backed securities and other asset-backed securities), floating rate loans, and other obligations to repay money borrowed. Of the funds investments in debt instruments, MFS may invest up to 100% of these investments in below investment grade quality debt instruments. MFS may at times invest a significant percentage of the fund's assets in short-term government securities, cash and/or cash equivalents. Cash equivalents include money market instruments and a money market fund advised by MFS. MFS invests the funds assets in U.S. and foreign securities, including emerging market securities. MFS normally invests the fund's assets across different industries, sectors, countries, and regions, but MFS may invest a significant percentage of the funds assets in issuers in a single industry, sector, country, or region. MFS may invest a significant percentage of the funds assets in a single issuer or a small number of issuers. MFS uses an active bottom-up investment approach to buying and selling investments for the fund. Investments are selected primarily based on fundamental analysis of individual issuers and instruments. Quantitative screening tools that systematically evaluate issuers and instruments may also be considered. In managing the fund, MFS seeks to reduce the volatility of the funds returns relative to the global equity markets, as represented by the MSCI World Index, over a full market cycle. In light of the funds principal investment strategies described above, MFS believes it is reasonable to measure the funds performance (net of fund expenses) over a full market cycle relative to the performance of (i) the MSCI World Index and (ii) the ICE BofA 0-3 Month U.S. Treasury Bill Index plus 3% to 5%. MFS does not seek to achieve a specific rate of return in managing the fund and there is no assurance that the fund will outperform the MSCI World Index or the ICE BofA 0-3 Month U.S. Treasury Bill Index over the long term or for any year or period of years. The term "prudent investor" can suggest different meanings to different investors and the use of the term "prudent investor" in the fund's name is not meant to suggest the fund will follow a specific investment strategy other than the principal investment strategies disclosed above. Show less