Fidelity Money Market Fund (SPRXX), part of Fidelity Hereford Street Trust, is a prime money market mutual fund that seeks a high level of current income consistent with the preservation of capital and liquidity. The fund invests primarily in U.S. dollar-denominated money market securities, including repurchase agreements, reverse repurchase agreements, commercial paper, certificates of deposit, and corporate notes; it intends to allocate at least 25% of its assets to the financial services sector. Offered with a total expense ratio of 0.42%, no minimum initial investment, and daily liquidity, SPRXX targets retail and institutional investors seeking short-term cash management solutions within the prime money market category.
Headquartered in Boston, Massachusetts, the fund operates under Fidelity Investments, founded in 1946, with global reach through its parent company's extensive network across the United States and international markets. Fidelity Investments manages the fund as part of its broad lineup of money market offerings, including U.S. Treasury & Government funds, retail prime funds like SPRXX, and retail municipal funds, serving brokerage, retirement, and wealth management clients worldwide.
In recent developments, Fidelity has expanded its money market ecosystem amid rising assets under management, with total money market fund industry assets approaching $7 trillion as of mid-2025; the firm's prime funds, including SPRXX, benefited from increased Treasury supply post-debt ceiling and shifting rate expectations, enabling portfolio maturity extensions. Fidelity launched new exchange-traded funds and digital asset products in 2025, such as Fidelity Crypto for IRAs and municipal bond ETFs, while maintaining high credit ratings for its money market funds like AAAm from S&P. No major acquisitions, mergers, or structural changes specific to SPRXX were reported in 2024-2025, with focus remaining on yield optimization and liquidity in a stable regulatory environment.