The Russell Indexes are a family of global equity indices that allow investors to track the performance of distinct market segments worldwide. Many investors use mutual funds or exchange-traded funds based on the Russell Indexes as a way of gaining exposure to certain portions of the U.S. stock market. Additionally, many investment managers use the Russell Indexes as benchmarks to measure their own performance. Russell's index design has led to more assets benchmarked to its U.S. index family than all other U.S. equity indexes combined.