Interest Rates: Money market fund prices are inversely related to interest rates. When interest rates rise, the yield on new investments increases, making existing, lower-yielding money market fund shares less attractive, potentially causing their price to decrease slightly. Conversely, falling interest rates can make existing shares more attractive, potentially increasing their price marginally.

Credit Risk: The creditworthiness of the securities held by the money market fund impacts its price. If the issuers of these securities (e.g., corporations or municipalities) experience a downgrade in their credit rating or default, the fund's price could decline.

Fund Expenses: The operating expenses of the money market fund, such as management fees and administrative costs, are deducted from the fund's earnings. Higher expenses can reduce the overall yield and potentially affect the attractiveness of the fund, indirectly influencing its price.

Supply and Demand: General market conditions and investor sentiment can influence the demand for money market funds. Increased demand can put upward pressure on the price, while decreased demand can lead to price declines. This effect is generally less pronounced than in other types of funds due to the inherent stability of money market funds.

Portfolio Maturity: Money market funds hold short-term debt instruments. As these instruments mature and are replaced with new ones, the overall yield and perceived risk of the fund can change, potentially affecting its price. Longer average maturity generally implies higher yield and risk.

Regulatory Changes: Changes in government regulations pertaining to money market funds can affect their structure, allowed investments, and risk profile. These changes can influence investor confidence and subsequently impact the fund's price.