Fund performance, interest rate and other factors affect the price of MSPXX.US. Fund Performance: A fund's historical returns and overall performance heavily influence investor demand and the fund's net asset value (NAV).

Interest Rates: Changes in prevailing interest rates affect the yield and attractiveness of money market funds like MSPXX.US, impacting investor flows.

Credit Quality: The creditworthiness of the securities held within the fund's portfolio (government bonds, corporate paper) can influence the perceived risk and thus its price.

Economic Conditions: Overall economic factors such as inflation, GDP growth, and employment rates can indirectly impact investor sentiment and asset allocation decisions, affecting demand for MSPXX.US.

Liquidity: The ease with which investors can buy or sell shares of MSPXX.US affects the fund's price, particularly during periods of market stress or uncertainty.

Management Fees: The fund's expense ratio, representing management fees and other costs, impacts the net return and ultimately the fund's attractiveness to investors.

Investor Sentiment: General market sentiment and risk appetite can influence investor demand for money market funds, pushing prices up or down.

Regulatory Changes: Changes in regulations pertaining to money market funds can influence the fund's structure, permissible investments, and investor protections, affecting its price.