The MSCI US Investable Market Consumer Discretionary 25/50 Index is a stock market index that measures the performance of companies in the consumer discretionary sector within the United States. This sector includes businesses that sell non-essential goods and services, such as retail, automotive, and entertainment. The index is designed to reflect the broader market by including a wide range of companies, from large corporations to smaller firms. The index follows specific rules to ensure diversification and limit concentration. It uses a 25/50 rule, which means that no single stock can exceed 25% of the index's total weight, and the combined weight of all stocks exceeding 5% cannot exceed 50%. This structure helps to reduce risk and promote stability within the index.