Fidelity Flex US Bond Index (Fidelity Flex U.S. Bond Index F) Fonds

The fund normally invests at least 80% of assets in bonds included in the Bloomberg U.S. Aggregate Bond Index. The Bloomberg U.S. Aggregate Bond Index is a broad based, flagship benchmark that measures the investment grade, U.S. dollar-denominated, fixed-rate taxable bond market. The index includes Treasuries, government-related and corporate securities, mortgage-backed securities, asset-backed securities and collateralized mortgage-backed securities.