The S&P 500, the Nasdaq 100 and the Dow Jones Industrial Average are the three most followed US stock indices. They share many of the same companies but are built differently: the S&P 500 weights about 500 companies by market value, the Nasdaq 100 weights 100 non-financial Nasdaq companies by market value with caps, and the Dow weights 30 companies by share price. Those rules decide how each one moves.
Key takeaways
- The S&P 500 is the broadest of the three and the usual measure of “the US market”.
- The Nasdaq 100 is the most concentrated in technology and usually the most volatile.
- The Dow is the narrowest and the only one weighted by share price.
- On most days all three move in the same direction; the size of the move differs.
- Holding two of them in the same direction mostly repeats one position.
| S&P 500 | About 500 companies · market value weighted · common symbol US500 |
|---|---|
| Nasdaq 100 | 100 non-financial Nasdaq companies · modified market value · US100 |
| Dow Jones | 30 companies · price weighted · US30 |
| Shared cash hours | 09:30–16:00 New York |
| Largest shared members | The biggest US technology and consumer companies |
| Symbols at Marketsall | US500, US100, US30 |
The three indices side by side
| Feature | S&P 500 | Nasdaq 100 | Dow Jones |
|---|---|---|---|
| Number of companies | About 500 | 100 | 30 |
| Weighting | Float-adjusted market value | Modified market value, with caps | Share price |
| Exchanges | NYSE and Nasdaq | Nasdaq only | NYSE and Nasdaq |
| Financial companies | Included | Excluded | Included |
| Technology weight | About a third | Well over half | Moderate |
| Selection | Committee, with size and profit rules | Largest by market value | Committee |
| First published | 1957 (500 stocks) | 1985 | 1896 |
| Typical volatility | Medium | Highest | Lowest to medium |
| Common CFD symbol | US500 | US100 | US30 |
| Guide | US500 guide | Nasdaq 100 guide | Dow guide |
Why do the three indices move by different amounts?
Because they hold different mixes. On a day when bond yields fall and technology rallies, the Nasdaq 100 usually rises most, the S&P 500 less and the Dow least. On a day when banks and industrials lead, the order can reverse. Over 2022, when rates rose quickly, the Nasdaq 100 fell about a third, the S&P 500 about a fifth and the Dow less than a tenth.
| Conditions | Usually moves most | Usually moves least |
|---|---|---|
| Falling bond yields, tech rally | Nasdaq 100 | Dow |
| Rising bond yields | Nasdaq 100 (down) | Dow |
| Strong growth, banks and industrials lead | Dow or S&P 500 | Nasdaq 100 |
| Broad sell-off | Nasdaq 100 | Dow |
| Earnings from the largest technology companies | Nasdaq 100 | Dow |
Which index fits which view?
| Your view | Index that expresses it most directly |
|---|---|
| The US market as a whole will rise or fall | S&P 500 |
| Technology and growth shares will outperform | Nasdaq 100 |
| Interest rates will fall sharply | Nasdaq 100 is the most sensitive |
| Industrial and financial companies will lead | Dow, or the S&P 500 |
| A specific high-priced Dow member will move | The Dow reacts more than the others |
The overlap is large: the biggest companies sit in all three. Holding US500 and US100 in the same direction is close to one larger position. See correlated positions.
Comparing position sizes across the three
The index levels are very different, roughly 6,500 for the S&P 500, over 20,000 for the Nasdaq 100 and over 40,000 for the Dow at illustrative levels. A move of 100 points means about 1.5% in the first, 0.5% in the second and 0.25% in the third. Always compare in percentage and money terms, using the value per point in each symbol’s specification.
Hours and clock changes are in index CFD trading hours; earnings timing is in how stock CFDs behave around earnings season.
What it costs to trade US index CFDs as a CFD
All three are traded as index CFDs, with the same cost components. See what a CFD is and index trading.
| Cost | When it applies | Note for US index CFDs |
|---|---|---|
| Spread | Every trade, at entry | Tightest in the US cash session for all three |
| Commission | Depends on instrument and account type | Shown in the symbol specification in MetaTrader 5 |
| Swap / overnight financing | Positions held past the daily rollover | Charged daily on positions held past the rollover. |
| Dividend adjustment | Cash-based index CFDs, when constituent shares go ex-dividend | Long positions are typically credited and short positions debited, so that the index’s fall on the ex-dividend date creates no profit or loss. |
| Contract rollover | Only if the CFD is based on a futures contract | The price adjusts when the underlying contract changes. |
| Slippage | Fast markets, gaps, news | Most likely at the cash open and after-hours earnings |
Key risks
Overlap. Positions in two or three US indices can amount to one concentrated bet.
Point confusion. The same number of points means very different percentages.
After-hours news. Results from the largest companies move all three. See gap risk.
Leverage. See how leverage increases trading risk.
Risk warning. Trading CFDs carries a high level of risk since leverage can work both to your advantage and disadvantage. As a result, the products offered on this website may not be suitable for all investors because of the risk of losing all of your invested capital. You should never invest money that you cannot afford to lose, and never trade with borrowed money.
How to trade US index CFDs at Marketsall
At Marketsall the S&P 500 is listed as US500. The Nasdaq 100 and the Dow Jones are listed as US100 and US30. Read the symbol specification for contract size, margin and swap rates before a first trade; how to read contract specifications on MT5 shows where they are. Practise on a demo account first, keeping in mind the differences covered in demo vs live accounts, and set the position size before opening the ticket with position sizing.
Frequently asked questions
What is the difference between the S&P 500, Nasdaq 100 and Dow Jones?
The S&P 500 tracks about 500 large US companies weighted by market value. The Nasdaq 100 tracks the 100 largest non-financial companies on Nasdaq, also by market value with caps, and is dominated by technology. The Dow tracks 30 companies weighted by share price.
Which is more volatile, the Nasdaq 100 or the S&P 500?
The Nasdaq 100 is usually more volatile. It is concentrated in technology and growth companies, which react more strongly to interest rates and earnings expectations. It tends to rise more in rallies and fall more in sell-offs.
Why is the Dow different from the other two?
The Dow is weighted by share price rather than company size and holds only 30 stocks. A company with a high share price therefore influences the Dow more than a larger company with a low share price, which does not happen in the S&P 500 or Nasdaq 100.
Which US index is best for tracking the whole market?
The S&P 500. It covers roughly 80% of the value of the US stock market across all sectors, while the Nasdaq 100 excludes financial companies and the Dow holds only 30 stocks.
Do the S&P 500, Nasdaq and Dow move together?
Usually in the same direction, because they share many of the largest companies and respond to the same economic news. The size of the moves differs: the Nasdaq 100 usually moves most and the Dow least.
Related reading
Turn index points into dollars
At Marketsall the S&P 500 is listed as US500. Look up what one point of it is worth with the MT5 contract specification guide, then turn a planned stop distance into money using position sizing.
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