Understanding the Dow Jones Industrial Average (DJIA)

Understanding the Dow Jones Industrial Average (DJIA)

4 Min.

The Dow Jones Industrial Average (DJIA), commonly known as "The Dow," is a renowned stock market index in the United States, capturing the price movements of 30 major American companies. Founded in 1896 by Charles H. Dow and Edward Jones, it serves as a benchmark for overall market conditions and the U.S. economy. This article explores the basics of the DJIA, its calculation method, and what it signifies.


The Dow Jones Industrial Average, often referred to as "The Dow," holds a significant place in the world of finance. It was established on May 26, 1896, by Charles H. Dow and Edward Jones. At its inception, the Dow comprised 12 industrial-company stocks and provided a numeric representation of market trends. The initial average was an impressive 40.94.

Components of the DJIA

Today, the DJIA consists of 30 prominent American companies, chosen from various sectors of the economy. Notably, the transportation and utility industries are excluded from this index, as they are covered by separate indexes known as the Dow Jones Transportation Average (DJTA) and Dow Jones Utility Average (DJUA). The current roster features industry giants like Apple, Goldman Sachs, Microsoft, Coca-Cola, Boeing, and Chevron. Remarkably, General Electric, the sole corporation included since 1896, was eventually removed.

The DJIA is not static; its components change over time based on specific non-quantitative criteria. Companies with a strong growth record and broad investor interest are considered for inclusion, ensuring that the index remains reflective of evolving market dynamics.

Calculating the DJIA

Calculating the DJIA has evolved significantly since its inception. In the early years, Charles Dow performed manual calculations, summing up the prices of the 12 stocks and dividing the result by 12. In 1923, Arthur "Pop" Harris assumed the responsibility for these calculations. After his retirement in 1963, computers took over this task.

Price-Weighted Index

The DJIA is a price-weighted index, which means that stocks with higher share prices carry greater weight in the index. Instead of dividing by the number of stocks in the average, as is done in an arithmetic average, the sum of the component stock prices is divided by a special divisor. This Dow divisor is continuously adjusted to mitigate the impact of stock splits, dividends, or corporate spinoffs, ensuring the index remains consistent. Consequently, the DJIA is influenced solely by changes in stock prices, with higher-priced stocks having a more substantial impact.

Economy’s Benchmark

The DJIA is essentially a reflection of the weighted average of the stock prices within it, serving as a price in itself. A decrease in the DJIA implies that the stocks can be obtained for a lower price than before, indicating a decline in their overall value. Conversely, an increase in the DJIA reflects rising share prices among its constituent companies, suggesting optimism in the market.

Over time, the DJIA serves as a barometer for the broader economy. Notably, its largest single-day percentage drop occurred on October 19, 1987, with a staggering 22% decline. The second-largest drop, a 12.9% decrease, happened on March 16, 2020, coinciding with periods of financial turmoil in the United States.

However, it's crucial to remember that a surge in the DJIA can result from a substantial rise in the share price of a single company, which may outweigh the decline in others. Therefore, a higher DJIA may not necessarily indicate that the company you're invested in is performing better. The index gauges the collective trend of all 30 stocks, with direction determined by the balance between rising and falling share prices.


The Dow Jones Industrial Average, known as "The Dow," remains an iconic symbol of the U.S. stock market. Founded in 1896, it has evolved from a 12-stock index to a collection of 30 diverse companies. Calculated as a price-weighted index, the DJIA reflects the average share price of its components and serves as a benchmark for market conditions and the U.S. economy. While it has experienced significant market fluctuations, understanding its composition and calculation method is essential for investors and financial professionals navigating the complexities of the stock market.

Dow Jones Industrial Average (DJIA)
Dow Jones Transportation Average (DJTA)
Dow Jones Utility Average (DJUA)