S&P 500
The Standard and Poor's 500, or simply the S&P 500,[5] is a stock market index tracking the stock performance of 500 large companies listed on stock exchanges in the United States. It is one of the most commonly followed equity indices. As of December 31, 2020, more than $5.4 trillion was invested in assets tied to the performance of the index.[2]
 S&P 500 Index from 1950 to 2016 | |
| Foundation | March 4, 1957[1] |
|---|---|
| Operator | S&P Dow Jones Indices[2] |
| Exchanges | |
| Trading symbol |
|
| Constituents | 503[2] |
| Type | Large-cap[2] |
| Market cap | US$33.8 trillion (as of December 31, 2022)[3] |
| Weighting method | Free-float capitalization-weighted[4] |
| Related indices | |
| Website | www |
The S&P 500 index is a free-float weighted/capitalization-weighted index. As of August 31, 2022, the nine largest companies on the list of S&P 500 companies accounted for 27.8% of the market capitalization of the index and were, in order of highest to lowest weighting: Apple, Microsoft, Alphabet (including both class A & C shares), Amazon.com, Tesla, Berkshire Hathaway, UnitedHealth Group, Johnson & Johnson and ExxonMobil.[3] The components that have increased their dividends in 25 consecutive years are known as the S&P 500 Dividend Aristocrats.[6]: 25
The index is one of the factors in computation of the Conference Board Leading Economic Index, used to forecast the direction of the economy.[7]
The index is associated with many ticker symbols, including ^GSPC,[8] .INX,[9] and $SPX, depending on market or website.[10]
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.[11][12]
The average annualized return since its inception in 1928 through Dec. 31, 2021, is 11.82%. The average annualized return since adopting 500 stocks into the index in 1957 through Dec. 31, 2021, is 11.88%.