Federal Funds Rate: Changes in the Federal Funds Rate, set by the Federal Reserve, directly influence DTBXX's yield and price. Higher rates increase yields, making the fund more attractive and potentially increasing its price.

Treasury Bill Yields: DTBXX invests primarily in U.S. Treasury bills. Fluctuations in T-bill yields directly affect the fund's returns and consequently, its price. Rising T-bill yields generally push DTBXX's price higher.

Demand for Money Market Funds: Increased demand for safe, liquid investments like DTBXX can drive up its price, especially during times of economic uncertainty or market volatility.

Fund Management Fees: The fees charged by the fund's management team impact the net yield to investors. Higher fees can reduce the fund's attractiveness, potentially affecting its price negatively.

Economic Conditions: Overall economic health, including inflation and employment data, influences interest rate expectations and, therefore, DTBXX's yield and price. Stronger economic data might lead to higher interest rate expectations.

Supply of Treasury Bills: An increase in the supply of T-bills could put downward pressure on their yields, potentially decreasing DTBXX's attractiveness and price.