This index-tracking fund aims to mirror the performance of a specific benchmark, the Standard & Poor's National AMT-Free Municipal Bond Index, which represents the investment-grade segment of the U.S. municipal bond market. It achieves this by employing a sampling strategy, carefully selecting a portion of the index's holdings to replicate its overall characteristics. A minimum of 80% of its assets will be invested in securities included in this target index. Crucially, under typical market conditions, at least 80% of the fund's portfolio will consist of bonds generating income that is exempt from both federal income tax and the federal alternative minimum tax (AMT). A primary risk is its sensitivity to interest rate fluctuations: rising rates can lead to a decrease in bond prices, while falling rates may eventually reduce the income distributed by the fund. This fund is designed for investors seeking potentially tax-free federal income who are comfortable with moderate swings in both investment value and distributed income. To maintain diversification, for 75% of its total assets, the fund generally restricts its holdings: it won't acquire more than 10% of an issuer's voting securities, nor will it invest more than 5% of its total assets in a single issuer's securities. Exceptions to these limits apply when necessary to match the target index's composition or when investing in U.S. government or agency obligations.