Normally investing at least 80% of assets in investment-grade debt securities (those of medium and high quality) of all types that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have positive environmental, social and governance (ESG) characteristics and repurchase agreements for those securities.Evaluating each security in which the fund invests using both a traditional bond credit, structure and relative value analysis and a consideration of the Adviser's judgment about the security's ESG characteristics. When assessing a security's ESG characteristics and its eligibility for purchase, the Adviser considers the following, where available: (i) the sustainability practices of the security's issuer or sponsor, as applicable (each, an "issuer"), based on an evaluation of such issuer's individual ESG profile; (ii) ESG factors related to the security's underlying pool of assets; and (iii) any third-party designation as a green, sustainable or sustainability-linked bond. A security's positive ESG characteristics can be determined under any of those three factors. Using the Adviser's proprietary ESG ratings process to evaluate the current state of an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and also provide a qualitative forward-looking assessment of an issuer's sustainability outlook provided by the Adviser's fundamental research analysts and ESG team. The Adviser's ESG ratings of issuers are derived from multiple factors, including an issuer's environmental profile, which may include, but is not limited to, carbon and toxic emissions, water management, waste management, vulnerability to the physical impacts of climate change, and research and investment into products, services, and energies that reduce emissions and/or provide opportunities to transition to less carbon-intensive products or operations. An assessment of an issuer's social profile includes, but is not limited to, its approach to diversity and inclusion, human capital management, data privacy, product safety and human rights. With respect to governance, the independence and diversity of an issuer's board, its compensation practices and board oversight of critical ESG issues are considered as part of the assessment. These factors are weighted based on how material the Adviser believes each factor is to an issuer's financial outlook, and not all factors may be applicable to all issuers. Issuers with an above average ESG rating as determined by the Adviser are considered to have positive ESG characteristics and well-managed ESG risks. Investing in debt securities of issuers that the Adviser believes deliver tangible environmental or social impact through core business operations. An assessment of the impact characteristics of an issuer may involve corporate engagement and an analysis of issuer alignment with the United Nations Sustainable Development Goals using qualitative analysis as well as proprietary or third-party data. For example, issuers that provide access to clean water, education, or clean energy through their core business may be considered to deliver tangible impact. When evaluating securitized debt securities (including mortgage-backed securities, commercial mortgage-backed securities, and other asset-backed securities), generally considering the issuer's ESG rating along with ESG factors related to the underlying pool of assets, such as energy efficiency and environmental impact of the underlying assets; providing access to affordable housing or opportunities for first time home ownership; and compliance with fair lending laws. In addition to its focus on debt securities with positive ESG characteristics, analyzing the credit quality of the issuer, security-specific features, current and potential future valuation, and trading opportunities to select investments.Normally maintaining a duration of 1 year or less.Managing the fund to have similar overall interest rate risk to the Bloomberg US Treasury Bill: 6-9 Months Index.Normally maintaining a dollar-weighted average maturity of two years or less.Allocating assets across different market sectors and maturities.Investing more than 25% of total assets in the financial services industries.Investing in domestic and foreign issuers.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.Employing sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Sustainable Investing Exclusions" for additional information.