The Dow Jones Industrial Average (DJIA), also known as the Dow 30, is a stock market index that tracks 30 large, publicly-owned blue-chip companies trading on the New York Stock Exchange and the NASDAQ. The Dow Jones is named after Charles Dow, who created the index in 1896 along with his business partner Edward Jones.

The DJIA is the second oldest U.S. market index; the first was the Dow Jones Transportation Average.

Historical Chart(Log Scale)

Composition

The index is often re-evaluated to replace companies that no longer meet the listing criteria with those that do. By 1928, the Index had grown to its current level of 30 components. Its composition has changed a total of 60 times since then.

The most recent large-scale change to the composition of the Dow prior to 2020 took place in 1997. At this time, four of the index’s components were replaced: Travelers’ Group replaced Westinghouse Electric; Johnson & Johnson replaced Bethlehem Steel; Hewlett-Packard took over Texaco’s spot, and Wal-Mart replaced Woolworths.

Two years later, in 1999, four more components of the Dow were changed, when Chevron, Sears Roebuck, Union Carbide, and Goodyear Tire were dropped while Home Depot, Intel, Microsoft, and SBC Communications were added.

On June 26, 2018, Walgreens Boots Alliance, Inc. replaced General Electric Company. In addition, United Technologies merged with Raytheon Company and the new corporation entered the index as Raytheon Technologies, while DowDuPont spun off DuPont and was replaced by Dow Chemical Company in 2020 and 2019, respectively.

On Aug. 24, 2020, Salesforce, Amgen, and Honeywell were added to the Dow, replacing ExxonMobil, Pfizer, and Raytheon Technologies.

Issues with market representation

With the inclusion of only 30 stocks, critics such as Ric Edelman argue that the DJIA is an inaccurate representation of overall market performance compared to more comprehensive indexes such as the S&P 500 Index or the Russell 3000 Index.

Additionally, the DJIA is criticized for being a price-weighted index, which gives higher-priced stocks more influence over the average than their lower-priced counterparts, but takes no account of the relative industry size or market capitalization of the components. For example, a $1 increase in a lower-priced stock can be negated by a $1 decrease in a much higher-priced stock, even though the lower-priced stock experienced a larger percentage change.