Interest Rates: Changes in interest rates, particularly by the Federal Reserve, impact bond yields and prices. Rising rates generally cause bond prices to fall, and vice versa.

Credit Quality: The creditworthiness of the bonds held in the fund affects its price. Downgrades can lower the fund's value, while upgrades can increase it.

Inflation Expectations: If investors anticipate higher inflation, bond yields typically rise to compensate for the erosion of purchasing power, thus lowering bond prices.

Economic Growth: A strong economy can lead to higher interest rates, potentially decreasing bond prices, while a weaker economy might lead to lower rates, boosting prices.

Market Sentiment: Overall investor confidence and risk appetite can influence bond demand and prices. Periods of uncertainty may drive investors toward safer assets like bonds.

Fund Flows: Large inflows into or outflows from the fund can affect its price, as the fund manager buys or sells bonds to accommodate these changes.

Maturity & Duration: Bonds with longer maturities are more sensitive to interest rate changes. The fund's duration, a measure of this sensitivity, is a key factor.

Supply & Demand: The supply of and demand for municipal bonds in the market affects their prices, and consequently the fund's value.