List of S&P 500 companies

The S&P 500 is a stock market index maintained by S&P Dow Jones Indices. It comprises 503 common stocks issued by 500 large-cap companies traded on American stock exchanges, including the 30 companies that make up the Dow Jones Industrial Average. The index represents about 80 percent of the American equity market by capitalization. It is weighted by free-float market capitalization, meaning more valuable companies have a greater influence on the index. The constituents and their weights are updated regularly based on rules published by S&P Dow Jones Indices. Although referred to as the S&P 500, the index includes 503 stocks due to three of its component companies having two share classes.