The NASDAQ-100 is a stock market inex of 100 of the largest domestic and international non-financial companies listed on the NASDAQ stock exchange, it is a modified market value-weighted index; the companies weights in the index are based on their market capitalization, with certain rules capping the influence of the largest components. It does not contain financial companies, and includes companies incorporated outside the United States; both of these factors differentiate this index from the S&P 500 and the Dow Jones Industrial Average.