Strategy. Under normal circumstances, the Fund will invest substantially all (and at least 80%) of its net assets in the equity securities included in the Index, in weightings that approximate the relative composition of the securities contained in the Index, and in Index futures approved by the Commodity Futures Trading Commission. The Index is a free float-adjusted market capitalization index consisting of 504 stocks and is a widely recognized measure of large-cap U.S. equities. As of May 30, 2025, the approximate market capitalization of the companies in the Index was between $153.68 million to $3.42 trillion. It is rebalanced quarterly. The Fund generally rebalances its portfolio in accordance with the Index. NTI uses a passive or indexing approach to try to … Show more… Under normal circumstances, the Fund will invest substantially all (and at least 80%) of its net assets in the equity securities included in the Index, in weightings that approximate the relative composition of the securities contained in the Index, and in Index futures approved by the Commodity Futures Trading Commission. The Index is a free float-adjusted market capitalization index consisting of 504 stocks and is a widely recognized measure of large-cap U.S. equities. As of May 30, 2025, the approximate market capitalization of the companies in the Index was between $153.68 million to $3.42 trillion. It is rebalanced quarterly. The Fund generally rebalances its portfolio in accordance with the Index. NTI uses a passive or indexing approach to try to achieve the Funds investment objective. Unlike many investment companies, the Fund does not try to beat the index it tracks and does not seek temporary defensive positions when markets decline or appear overvalued. NTI will buy and sell securities in response to changes in the Index as well as in response to subscriptions and redemptions. The Fund generally invests in substantially all of the securities in the Index in approximately the same proportion as the Index (i.e., replication). In certain circumstances, however, the Fund may not hold every security in the Index or in the same proportion as the Index, such as to improve tax efficiency or when it may not be practicable to fully implement a replication strategy. Rather, it will use an optimization strategy to seek to construct a portfolio that minimizes tracking error versus the Index while managing transaction costs and realized capital gains and losses. The Fund intends to be diversified in approximately the same proportion as the Index is diversified. The Fund may become non-diversified, as defined in the Investment Company Act of 1940 (the 1940 Act), solely as a result of a change in relative market capitalization or index weighting of one or more constituents of the Index. A non-diversified fund can invest a greater percentage of its assets in a small group of issuers or in any one issuer than a diversified fund can. Shareholder approval will not be sought if the Fund becomes non-diversified due solely to a change in the relative market capitalization or index weighting of one or more constituents of the Index. In seeking to track the performance of the Index, from time to time the Fund may have a focused investment (i.e., investment exposure comprising more than 15% of its total assets) in one or more particular sectors. As of March 31, 2025, the Fund had a focused investment in the information technology sector. NTI expects that, under normal circumstances, the quarterly performance of the Fund, before fees and expenses, will track the performance of the Index within a 0.95 correlation coefficient. The Index is created and sponsored by S&P Dow Jones Indices (S&P), as the index provider. S&P determines the composition and relative weightings of the securities in the Index and publishes information regarding the market value of the Index. S&P does not endorse any of the securities in the Index. It is not a sponsor of the Stock Index Fund and is not affiliated with the Fund in any way. Show less