The Fortune 500 and the S&P 500 are different measures of companies in the United States, and they are compiled by two different companies. The Fortune 500 is an annual list of the 500 largest companies using the most recent revenue figures and includes public and private companies. The S&P 500 is an index of 500 public companies that are selected by the S&P Index Committee. The main difference between the two lists is that one includes private companies, while the other only includes publicly traded large-cap companies.
The Fortune 500 is an annual list of the 500 largest companies in the U.S. using the most recent figures for revenues. It is compiled and managed by Fortune magazine and includes both public and private companies. The Fortune 500 can be used to gauge the health of the overall U.S. economy. When many companies of a sector are removed from the list, it may signal weakness in that particular sector.
The S&P 500 is an index composed of 500 large-cap stocks that represent the leading industries of the U.S. economy. The S&P Index Committee chooses which 500 companies should be placed in the index by analyzing liquidity, industry and market capitalization of publicly traded companies. Large-cap companies are those that have a market capitalization of over $10 billion. The S&P 500 measures the overall risk, return and performance of the large-cap equities market. It is the main benchmark that investors and practitioners use to gauge the health of U.S. large-cap stocks.