The Dow Jones Industrial Average (DJIA) is a stock market index that tracks the performance of 30 large, publicly traded companies in the United States. The index is calculated by taking the average of the stock prices of these companies and is often used as a barometer of the performance of the U.S. stock market as a whole. The DJIA is one of the oldest and most well-known stock market indices in the world and includes companies such as Apple, Coca-Cola, and IBM. Its value changes daily based on the stock performance of the companies included in the index. The Index is named after Charles Dow and Edward Jones who founded Dow Jones and Company.