Interest Rates: The primary driver is short-term interest rates. CGMXX, a money market fund, invests in short-term debt securities. When interest rates rise, the yields on these securities increase, leading to a higher fund yield and potentially a higher share price.

Federal Reserve Policy: The Fed's monetary policy decisions significantly influence short-term rates. Actions like raising or lowering the federal funds rate directly impact the yield of instruments held by CGMXX.

Economic Conditions: Strong economic growth often leads to higher interest rates as demand for borrowing increases. Conversely, economic slowdowns may prompt the Fed to lower rates, affecting CGMXX's yield.

Credit Risk: While CGMXX primarily invests in high-quality securities, changes in perceived creditworthiness of issuers can impact the fund's valuation, although this is typically minimal due to the fund's conservative investment strategy.

Supply and Demand: Increased demand for money market funds can slightly influence share price. However, the price is designed to remain stable around $1 per share, so this effect is limited.