Dow vs S&P 500 vs Nasdaq
When people ask "how did Wall Street do today?" they usually mean one of a few stock indices. Here is what each one measures and why they rarely move by exactly the same amount.
Live quotes shown are the ETFs that track each index (DIA = Dow, SPY = S&P 500, QQQ = Nasdaq-100, IWM = Russell 2000), via TradingView. ETF prices are not index points.
The indices at a glance
| Index | Members | Weighting | Popular tracking ETF |
|---|---|---|---|
| Dow Jones Industrial Average | 30 large US companies chosen by a committee | Price-weighted | DIA |
| S&P 500 | About 500 large US companies (slightly more share classes) | Float-adjusted market cap | SPY, IVV, VOO |
| Nasdaq Composite | Essentially all common stocks listed on Nasdaq (thousands) | Market cap | ONEQ |
| Nasdaq-100 | 100 of the largest non-financial companies listed on Nasdaq | Modified market cap | QQQ |
| Russell 2000 | About 2,000 small-cap US companies | Float-adjusted market cap | IWM |
Dow Jones Industrial Average
Launched by Charles Dow in 1896, the Dow is the oldest of the big US indices and contains just 30 stocks. It is price-weighted: a stock with a higher share price has more influence than one with a lower price, regardless of company size. A $10 move in any member moves the index by the same number of points, which is why stock splits change a company's influence on the Dow.
S&P 500
Maintained by S&P Dow Jones Indices, the S&P 500 covers roughly 80% of the value of the US stock market and is the benchmark most professional investors compare themselves to. Each company counts in proportion to the market value of its publicly tradable shares, so the largest companies dominate daily moves. Membership is decided by a committee using rules on size, liquidity and profitability.
Nasdaq Composite and Nasdaq-100
"The Nasdaq" in the news usually means the Nasdaq Composite, which includes nearly every stock listed on the Nasdaq exchange. The Nasdaq-100 is a narrower index of 100 of the largest non-financial Nasdaq companies and is the one tracked by the QQQ fund. Both lean heavily toward technology, so they tend to rise and fall more sharply than the Dow.
Russell 2000
The Russell 2000, from FTSE Russell, tracks smaller US companies. It is often used as a gauge of domestic economic sentiment because small companies earn most of their revenue in the US and are more sensitive to borrowing costs.
Why the indices move differently
- Different members: 30 blue chips vs. 500 large caps vs. thousands of Nasdaq listings.
- Different weighting: price weighting (Dow) vs. market-cap weighting (the rest).
- Different sector mix: the Nasdaq indices are tech-heavy; the Dow has more industrials, financials and health care.
- Points vs. percent: a 400-point Dow move and a 1% S&P move may be similar in percentage terms. Compare percentages, not points.
To see which stocks are driving the S&P 500 today, open the stock heatmap. For international indices such as the DAX, FTSE 100 and Nikkei 225, see the market overview.
Frequently asked questions
Which index is "the stock market"?
There is no single official one. The S&P 500 is the most widely used benchmark for the US market, while the Dow is the most quoted in news headlines.
Can I invest directly in an index?
No, an index is just a calculation. Investors use index funds or ETFs (such as SPY, QQQ or DIA) that hold the index's stocks.
Why does the Dow have so few stocks?
It was created in 1896, when calculating an average by hand made a small list practical. It has kept its 30-stock, price-weighted design for continuity.