Dow Jones Industrial Average - The Dow Jones Industrial Average, more frequently know simply as the Dow or the Dow Jones, is a stock market index made up of 30 of the largest publicly-owned companies based in the United States. It is a price weighted index meaning that the index's price is an average of the price of the 30 stocks that make it up. Though it is price weighted, this does not mean that every time there is split the index is completely changed, as they have factors to keep the value of the index consistent. 