The S&P 500 is a stock market index tracking the performance of 500 large companies listed on U.S. exchanges, widely regarded as the best gauge of large-cap U.S. equities.
Description: The S&P 500, introduced in 1957 by Standard & Poor's (now S&P Global), is a market-capitalization-weighted index of 500 leading publicly traded companies in the United States. It covers approximately 80% of the total U.S. equity market value, spanning all major sectors. The index is widely used as a benchmark for the overall U.S. stock market and is the basis for many index funds and ETFs, such as the SPDR S&P 500 ETF (SPY). Its composition is reviewed periodically to ensure representation of the largest and most influential companies. The S&P 500 is considered a leading indicator of U.S. economic health and is followed by investors globally.
Established / Launched: 1957
Founder / Issuer: S&P Global (formerly Standard & Poor's)
