The S&P 500 includes the 500 largest companies operating in all sectors of the American market. It is the flagship index that exposes, at a glance, 80% of the American economic activity by measuring the performance of the stocks (of these companies).
The S&P 500 takes into account the 500 best performing companies, whether they operate on the New York Stock Exchange (NYSE), which is the oldest and largest market capitalization exchange in the U.S., or on the second largest security exchange in the U.S., the NASDAQ (the first electronic exchange, whose acronym stands for National Associations of Securities Dealers Automated Quotations) The S&P 500 was created by Standard and Poor’s.