Bond Market Conditions: Interest rate movements, inflation expectations, and overall economic outlook significantly impact bond yields and thus the net asset value (NAV) of VWVSX.US.

Credit Risk: Changes in the creditworthiness of the municipal bonds held within the fund can affect their values. Downgrades lead to lower bond prices, and vice versa.

Fund Flows: Significant inflows or outflows from the fund can impact its NAV as the fund manager needs to buy or sell bonds, potentially affecting prices, especially for less liquid holdings.

Tax Law Changes: Alterations to tax laws, especially those impacting the tax-exempt status of municipal bonds, can heavily influence investor demand and thus VWVSX.US's price.

Supply of Municipal Bonds: The volume of newly issued municipal bonds in the market can affect existing bond prices. Increased supply might lead to lower prices.

Economic Growth: A strong economy typically results in higher interest rates, which negatively impacts bond values. Slower growth may lead to lower rates and higher bond values.