Dow Jones Industrial Average (DJIA)
What Is the Dow Jones Industrial Average?
The Dow Jones Industrial Average (DJIA), often simply called "the Dow," is a stock market index that tracks 30 prominent, publicly-owned companies trading on the New York Stock Exchange (NYSE) and Nasdaq.
The Dow Jones Industrial Average (DJIA) is the second-oldest US market index (after the Dow Jones Transportation Average) and serves as a premier benchmark for the American stock market. Created by Charles Dow and Edward Jones in 1896, it originally consisted of 12 industrial companies. Today, it tracks 30 of the most significant and influential companies in the United States, covering all industries except transportation and utilities. Often referred to simply as "the Dow," the index is a price-weighted average. This means that stocks with higher share prices have a greater influence on the index's performance than stocks with lower share prices, regardless of the company's total market value. This methodology is unique among major indices, which are typically weighted by market capitalization (like the S&P 500 or Nasdaq 100). The 30 components are household names, including Apple, Microsoft, Coca-Cola, Goldman Sachs, and Home Depot. Because it includes such well-established companies, the Dow is often seen as a proxy for the "blue-chip" sector of the market.
Key Takeaways
- The DJIA is one of the oldest and most widely followed stock market indices in the world, founded in 1896.
- It consists of 30 large-cap US "blue-chip" companies deemed to be leaders in their industries.
- Unlike the S&P 500 (which is market-cap weighted), the Dow is a price-weighted index.
- The components are selected by editors of The Wall Street Journal, not by a mathematical rule.
- The index is used as a barometer for the overall health of the US economy.
How the Dow Is Calculated (Price Weighting)
The calculation of the Dow is surprisingly simple but often misunderstood. Originally, it was just the sum of the stock prices divided by the number of stocks. Today, it uses a special "Dow Divisor" to account for stock splits, spin-offs, and other corporate actions over the last century. **Formula:** Sum of Component Stock Prices / Dow Divisor. Because of this price-weighting method: * A $1 move in a $300 stock (like UnitedHealth) has the same impact on the index as a $1 move in a $50 stock (like Verizon). * However, a 1% move in the $300 stock is a larger dollar amount ($3) than a 1% move in the $50 stock ($0.50). Therefore, higher-priced stocks drive the index's percentage performance much more than lower-priced stocks.
Critiques of the Dow
Many financial professionals consider the S&P 500 a better representation of the US market than the Dow for several reasons: 1. **Small Sample Size:** 30 companies is a tiny fraction of the thousands of public US companies. 2. **Price Weighting Bias:** A company's influence is based on its arbitrary stock price, not its actual size. For example, a massive company like Apple had less influence than a smaller company with a higher share price until Apple split its stock. 3. **Selection Bias:** The components are hand-picked by a committee, introducing a subjective element compared to rules-based indices.
Real-World Example: Stock Split Impact
In 2020, Apple (a Dow component) announced a 4-for-1 stock split. Before the split, Apple traded at roughly $500. It had a huge influence on the Dow due to this high price. After the split, Apple traded at $125. Mechanically, this reduced Apple's weight in the Dow by 75%, significantly lowering its impact on the index's daily moves. To compensate and keep the index level constant, the Dow Divisor was adjusted downward.
Advantages
* **History:** With over 125 years of data, it offers the longest continuous record of US market history. * **Stability:** The companies are mature, dividend-paying, and profitable, making the index less volatile than the Nasdaq. * **Simplicity:** It is easy for the public to understand "the market is up 100 points."
Disadvantages
* **Narrow Focus:** Ignoring tech-heavy growth stocks (until recently) means it often lags behind the broader economy. * **Arbitrary Weighting:** Price-weighting is theoretically flawed for measuring economic importance.
FAQs
The 30 companies change over time but always represent major sectors. Current members include Apple, Microsoft, Boeing, Chevron, McDonald's, Visa, and Walt Disney. General Electric (GE), an original member, was removed in 2018.
You can buy an ETF that tracks the index, such as the SPDR Dow Jones Industrial Average ETF Trust (DIA), commonly known as "Diamonds."
It means the calculated average of the 30 stock prices (divided by the divisor) has risen by 500 points. Since the index level is high (e.g., 35,000), a 500-point move is roughly 1.4%.
Historically, the US economy was driven by heavy industry (steel, oil, rail). While the name remains, the index now includes technology, healthcare, finance, and consumer goods, reflecting the modern service-based economy.
Rarely. Changes are made only when a company loses its prominence or to better reflect the economy. For example, Salesforce replaced Exxon Mobil in 2020 to increase tech exposure.
The Bottom Line
The Dow Jones Industrial Average is the grandfather of market indices. While arguably flawed in its methodology compared to modern indices like the S&P 500, its history and cultural significance make it the headline number for "the stock market" in the minds of millions. For investors, the Dow represents a portfolio of 30 of the safest, most profitable companies on earth. Tracking it offers a reliable, if somewhat narrow, view of American blue-chip performance.
More in Stock Market Indices
At a Glance
Key Takeaways
- The DJIA is one of the oldest and most widely followed stock market indices in the world, founded in 1896.
- It consists of 30 large-cap US "blue-chip" companies deemed to be leaders in their industries.
- Unlike the S&P 500 (which is market-cap weighted), the Dow is a price-weighted index.
- The components are selected by editors of The Wall Street Journal, not by a mathematical rule.