Federal Funds Rate: TOSXX's yield, and therefore its price, is heavily influenced by the Federal Reserve's target for the federal funds rate. Higher rates typically lead to higher yields and potentially a slightly lower price as newer, higher-yielding alternatives become available.

Treasury Bill Yields: As a money market fund primarily investing in short-term Treasury securities, changes in Treasury bill yields directly impact TOSXX's yield and price. Rising T-bill yields generally increase TOSXX's yield and can slightly decrease the price.

Demand for Short-Term Investments: High demand for safe, liquid short-term investments can drive down yields slightly, potentially increasing TOSXX's price marginally. Conversely, lower demand can increase yields and slightly decrease the price.

Fund Management Fees: The fund's expense ratio impacts the net yield to investors. Higher fees reduce the net yield, potentially making the fund less attractive and slightly impacting the price.

Overall Market Liquidity: General market liquidity conditions affect the prices of all securities, including those held by TOSXX. Periods of low liquidity can lead to price volatility and potentially impact TOSXX.

Economic Conditions: Economic factors like inflation and economic growth expectations influence interest rates, which in turn affect the yield and price of TOSXX.