The Fidelity SAI Total Bond Fund (FSMTX) is a mutual fund that primarily invests in a diverse portfolio of fixed-income securities, such as government and corporate bonds. It aims to provide investors with a steady stream of income and potential for capital appreciation while maintaining a low level of risk. The fund is managed by Fidelity Investments and utilizes a strategic allocation approach to select high-quality bonds with varying maturities and credit ratings. With a focus on total return, this fund may be suitable for investors seeking a conservative and balanced investment option.