Amex Composite and Nasdaq composite are some of the major stock indexes, according to Nasdaq. Other major stock indexes include the S&P 500 and the New York Stock Exchange.
The Nasdaq-100 Index is an altered capitalization-weighted index that monitors the efficiency of the 100 most actively traded and largest international and domestic Nasdaq-listed, non-financial securities, explains the U.S. Securities and Exchange Commission. The S&P 500 Composite Stock Price Index and the NYSE Composite Index stocks carry weights proportionate to the market capitalization of the stock and is capitalization-weighted. The S&P 500 provides an index of the 500 leading stocks in its industry in the economy of the United States. The NYSE Composite Index monitors price changes of New York Stock Exchange-listed common stocks.