Strategy. MFS (Massachusetts Financial Services Company, the fund's investment adviser) normally invests the funds assets primarily in debt instruments. Debt instruments include U.S. Government securities, corporate debt instruments, foreign government securities, securitized instruments (including mortgage-backed securities and other asset-backed securities), and other obligations to repay money borrowed. The funds dollar-weighted average effective maturity will normally not exceed five years. MFS generally invests substantially all of the funds assets in investment grade quality debt instruments. MFS invests the funds assets in U.S. securities and U.S. dollar-denominated foreign securities, which may include 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 … Show more… MFS (Massachusetts Financial Services Company, the fund's investment adviser) normally invests the funds assets primarily in debt instruments. Debt instruments include U.S. Government securities, corporate debt instruments, foreign government securities, securitized instruments (including mortgage-backed securities and other asset-backed securities), and other obligations to repay money borrowed. The funds dollar-weighted average effective maturity will normally not exceed five years. MFS generally invests substantially all of the funds assets in investment grade quality debt instruments. MFS invests the funds assets in U.S. securities and U.S. dollar-denominated foreign securities, which may include 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. 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 a particular market, segment of the market, or security, to increase or decrease interest rate exposure, or as alternatives to direct investments. Derivatives include futures, forward contracts, options, and swaps. 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 instruments and their issuers. Quantitative screening tools that systematically evaluate instruments may also be considered. In structuring the fund, MFS also considers top-down factors. Show less