S&P 500 ETFs - Friday, Sept. 7 By: TalkMarkets September 07, 2018 at 14:55 PM EDT The S&P 500 index is arguably the most well-known worldwide. It is based on the market cap of the 500 largest companies in the U.S. Read More >> Related Stocks: S&P 500 ETF Vanguard S&P 500 Ishares Core ETF SPDR S&P 500 ETF Trust