S&P 500® index is widely regarded as the best single gauge of large-cap U.S. equities. The index includes 500 leading companies and captures approximately 80% coverage of available market capitalization. S&P Dow Jones Indices. 

The Standard & Poor’s 500, often abbreviated as the S&P 500, or just the S&P, or its symbol SPX, #SPX, or $SPX, is an American stock market index based on the market capitalizations of 500 large companies having common stock listed on the NYSE or NASDAQ. The S&P 500 index components and their weightings are determined by S&P Dow Jones Indices.

S&P 500 has become a preferred index for U.S. stocks, unseating the Dow Jones Industrial Average (DJIA). The S&P 500 is perceived as more representative of the market because it is made up of significantly more companies than the DJIA’s 30. Investopedia

S&P 500. The index measures the performance of the large-cap segment of the market. Considered to be a proxy of the U.S. equity market, the index is composed of 500 constituent companies.

S&P 500 Index resources for quotes, charts, historical returns, total return, index methodology.

S&P 500 Index Website Standard & Poor’s

S&P U.S. Indices Methodology

S&P 500® index Fact Sheet

SPX – S&P 500 Index – MarketWatch

S&P 500® – S&P Dow Jones Indices

Standard & Poor’s 500 Index (S&P 500) – Investopedia

S&P 500 Index – CNNMoney.com

S&P 500 Index – Wikipedia

.SPX: S&P 500 Index – Stock Quote and News – CNBC

SPX Quote – S&P 500 Index – Bloomberg Markets Index performance for S&P 500 Index (SPX) including value, chart, profile & other market data.

S&P 500 – Yahoo Finance

^GSPC : Summary for S&P 500 – Yahoo Finance

S&P 500 – Morningstar

S&P 500 Index – Investing.com

S&P 500 Today – S&P 500 Index Today – ^GSPC – TheStreet

S&P 500 | FRED | St. Louis Fed  View data of the S&P 500, an index of the stocks of 500 leading companies in the US economy, which provides a gauge of the U.S. equity market.