The S&P 500 (Standard & Poor's 500) is a stock market index that tracks the performance of 500 leading publicly traded companies in the United States. Often used as a bellwether for the U.S. economy, it represents approximately 80% of the total market capitalization of U.S. public companies. The index is widely considered a key indicator of overall stock market performance. The S&P 500 was initially created in 1923 with 233 companies, then expanded to 500 companies on March 4, 1957.
The S&P 500 is managed by S&P Dow Jones Indices. Companies included must meet specific criteria, including a market capitalization greater than or equal to US$22.7 billion. The index is capitalization-weighted, meaning larger companies have a greater influence on its performance. As of January 2026, the ten largest components include Nvidia, Alphabet, Apple, Microsoft, Amazon, Broadcom, Meta Platforms, Tesla, Berkshire Hathaway and Eli Lilly. Recently, market leadership has begun to broaden within the S&P 500, with sectors like energy, materials, consumer staples, and industrials emerging as top performers. On February 10, 2026, the index reached 6,985 points. Martina L. Cheung is the President & Chief Executive Officer of S&P Global.