S&P 500

The Standard and Poor's 500, or simply the S&P 500,^[6] is a stock market index tracking the stock performance of 500 leading companies listed on stock exchanges in the United States. It is one of the most commonly followed equity indices and includes approximately 80% of the total market capitalization of U.S. public companies, with an aggregate market cap of more than $57.401 trillion as of August 29, 2025.^[2]

The S&P 500 index is a public float weighted/capitalization-weighted index. The ten largest companies on the list of S&P 500 companies account for approximately 38% of the market capitalization of the index and the 50 largest components account for 60% of the index. As of September 2025, the 10 largest components are, in order of highest to lowest weighting: Nvidia (7.2%), Microsoft (6.3%), Apple (5.9%), Alphabet (5.0%, including both class A & C shares), Amazon (4.1%), Meta Platforms (3.2%), Broadcom (2.8%), Tesla (2.3%), Berkshire Hathaway (1.8%), and JPMorgan Chase (1.4%).^[4] The components that have increased their dividends in 25 consecutive years are known as the S&P 500 Dividend Aristocrats.^[7] Companies in the S&P 500 derive a collective 72% of revenues from the United States and 28% from other countries.^[8]

The index is one of the factors in computation of the Conference Board Leading Economic Index, used to forecast the direction of the economy.^[9] The index is associated with many ticker symbols, including ^GSPC,^[10] .INX,^[11] and SPX, depending on market or website.^[12] The S&P 500 is maintained by S&P Dow Jones Indices, a joint venture majority-owned by S&P Global, and its components are selected by a committee.^[3]