Dow Jones Industrial Average
The most popular index that follows United States blue chips is the Dow Jones Industrial Average, a price-weighted average of 30 blue-chip stocks that are generally the leaders in their industry. All companies in the Dow Jones Industrial Average are blue-chips, but the Dow Jones Industrial Average is an index that does not include all companies that are blue chips. Nevertheless, it has been a widely followed indicator of the stock market since October 1, 1928.