The MSCI US Investable Market Industrials 25/50 Index is a stock market index that represents the performance of companies in the industrial sector of the United States. It includes a wide range of industries such as manufacturing, transportation, and aerospace, providing a comprehensive view of the industrial market. The index is designed to capture the performance of the investable market, meaning it includes companies that are accessible for investment. The "25/50" in the index name refers to specific diversification rules. These rules ensure that no single company can dominate the index, with a maximum weight of 25% for any one company and a combined weight of 50% for the top companies. This structure helps maintain a balanced representation of the industrial sector within the broader market.