Market Index
A composite measure that tracks the performance of a selected group of stocks representing a market or sector.
What is Market Index?
A market index is a hypothetical portfolio of securities representing a particular market segment, used to track the overall performance of that segment over time. Indices are constructed using various weighting methods — market-capitalization weighting (used by the S&P 500), price weighting (used by the Dow Jones Industrial Average), or equal weighting. Investors use indices as benchmarks to evaluate portfolio performance, and index funds or ETFs that track major indices have become the dominant form of passive investing. The most widely followed indices include the S&P 500, Nasdaq Composite, Dow Jones Industrial Average, and Russell 2000.
Example
The S&P 500 Index, maintained by S&P Dow Jones Indices, tracks 500 of the largest U.S. companies by market capitalization and represents approximately 80% of total U.S. equity market value. In 2024, the index returned approximately 25%, reaching an all-time high above 6,000 points.
Source: S&P Dow Jones Indices — S&P 500