The Dow Jones Industrial Average (DJIA), Dow Jones, or simply the Dow (/ˈdaʊ/), is a stock market index of 30 prominent companies listed on stock exchanges in the United States. The DJIA is one of the oldest and most commonly followed equity indexes. Many professionals consider it to be an inadequate representation of the overall U.S. stock market compared to a broader market index such as the S&P 500. The DJIA includes only 30 large companies. It is price-weighted, unlike stock indices which use market capitalization. Furthermore, the DJIA does not use a weighted arithmetic mean.