S&P 500
The Standard and Poor's 500, or sometimes known as the S&P 500, is  something that measures the stock market, looking at how well 500 of the largest companies listed on stock exchanges in the United States are doing. It is one of the most commonly used ways of looking at stocks for these companies. There is over $4.6 trillion invested in the companies that use how well companies are doing to know when to invest.