Normally investing at least 80% of assets in debt securities of all types and repurchase agreements for those securities. Debt securities are used by issuers to borrow money. The issuer usually pays a fixed, variable, or floating rate of interest, and must repay the amount borrowed, usually at the maturity of the security. Debt securities include corporate bonds, government securities (including Treasury securities), repurchase agreements, money market securities, mortgage and other asset-backed securities, loans and loan participations, and other securities, such as hybrids and synthetic securities, believed to have debt-like characteristics (e.g., securities classified as Tier 2 Regulatory capital, securities that rank above share capital in an insolvency waterfall, securities with maturity dates and non-cancellable interest payment structures).  A repurchase agreement is an agreement to buy a security at one price and a simultaneous agreement to sell it back at an agreed-upon price. Effective December 11, 2025, derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives.   Allocating assets across the full spectrum of the debt market, including investment-grade (those of medium and high quality), high yield and emerging markets debt securities across different maturities. In addition to the debt securities listed above, investments also will normally include lower-quality debt securities (those of less than investment-grade quality, also referred to as high yield debt securities or junk bonds), investment-grade securitized debt securities, floating rate loans and other floating rate securities, inflation-protected debt securities, preferred securities, contingent convertible securities, and securities of foreign issuers, including securities of issuers located in emerging markets. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. Investing in both U.S. dollar-denominated and non-U.S. dollar-denominated securities, and generally hedging the fund's foreign currency exposures utilizing forward foreign currency exchange contracts. Investing in collateralized loan obligations (CLO). Analyzing the credit quality of the issuer, security-specific features, current and potential future valuation, and trading opportunities to select investments. Engaging in transactions that have a leveraging effect on the fund, including investments in derivatives - such as swaps (interest rate, total return, and credit default), options, and futures contracts - and forward-settling securities, to adjust the fund's risk exposure. Investing in Fidelity's Central funds (specialized investment vehicles used by Fidelity® funds to invest in particular security types or investment disciplines) consistent with the asset classes discussed above.