Dow vs S&P 500 vs Nasdaq: Which Index Does Your Fund Track?

In the Dow vs S&P 500 vs Nasdaq comparison, the real difference is size and weighting. The Dow tracks 30 large US companies weighted by share price, the S&P 500 tracks about 500 large US companies weighted by market value, and the Nasdaq-100 tracks the 100 biggest non-financial companies listed on Nasdaq, also weighted by value.

If you are brand new to investing, start with our guide to index funds for beginners. Below, we compare what each index measures and which one your fund tracks.

Dow vs S&P 500 vs Nasdaq at a glance

What is the Dow Jones Industrial Average?

The Dow Jones Industrial Average, usually just "the Dow," is the oldest of the three. According to S&P Dow Jones Indices, Charles Dow began calculating his average of 12 industrial stocks in May 1896. Today it holds 30 large, well-known US companies chosen by a committee, and despite the name it is no longer limited to industrial businesses.

Transportation and utility companies are left out because they have their own separate Dow averages.

How price weighting works

This is the part most people miss when they look for the Dow Jones Industrial Average explained. The Dow is price-weighted, so a stock with a higher share price moves the index more than a stock with a lower one, no matter how big each company is.

Here is a simple made-up example. Company A trades at $400 a share and Company B at $40. If both rise 10%, Company A adds $40 to the sum of prices while Company B adds only $4. Company A has ten times the pull, even if Company B is the larger business by total value.

That quirk is also why stock splits matter. When a Dow company splits its shares, its price drops and its influence on the index shrinks, even though the business has not changed. A number called the divisor is adjusted so the split itself does not move the index. The official S&P 500 and Dow explainer walks through how both indexes are built.

What is the S&P 500?

The S&P 500 tracks about 500 large US companies across every major sector, from technology and health care to banks and energy. A committee at S&P Dow Jones Indices picks the members using published rules on size, trading activity and profitability.

It is weighted by float-adjusted market value. Market value (also called market capitalization) is the share price times the number of shares. "Float-adjusted" means only shares available to the public count. The biggest companies by value have the biggest effect, which mirrors how money is actually spread across the market.

Because it covers so much of the US stock market by value, the S&P 500 is the benchmark most professionals mean when they say "the market."

What is the Nasdaq? Composite vs Nasdaq-100

"The Nasdaq" can mean three different things, which is why it confuses so many people:

• The Nasdaq Stock Market: an exchange where shares are bought and sold, like the New York Stock Exchange.
• The Nasdaq Composite: an index of nearly every stock with a primary listing on Nasdaq, thousands of companies, weighted by market value. This is usually the "Nasdaq" number in news reports.
• The Nasdaq-100: the 100 largest non-financial companies listed on Nasdaq. This is the index most Nasdaq funds track.

The Nasdaq-100 uses modified market-value weighting. Big companies still count most, but Nasdaq's published rules cap how much weight the very largest can carry, so a few giants cannot take over the whole index.

S&P 500 vs Nasdaq: how much do they overlap?

Quite a lot. Many of the largest Nasdaq-100 companies, such as Apple, Microsoft and Nvidia, also sit near the top of the S&P 500, because both indexes weight by size. The big differences are what the Nasdaq-100 leaves out: banks, insurers and other financial companies, plus every company listed on the New York Stock Exchange instead of Nasdaq.

The result is a narrower, more growth-tilted index that tends to swing harder in both directions. If that tech tilt appeals to you, our guide to investing in AI as a beginner compares single stocks with ETFs.

Why do news headlines quote the Dow?

If the S&P 500 is the broader gauge, why does the news lead with the Dow? Three reasons:

• History: it has been published since 1896, so it has the longest track record and the most name recognition.
• Habit: newsrooms and viewers have used it as shorthand for the market for generations.
• Big-sounding numbers: the Dow's level is much higher than the S&P 500's, so its daily moves in points look dramatic.

That last point is the one to watch. A 400-point Dow drop sounds alarming, but what matters is the percentage change. Always compare indexes by percent, never by points. If all three fall around 1% on the same day, the market had one ordinary down day, not three separate crises.

Which index does your fund track?

Most beginners never buy "the Dow" or "the Nasdaq" directly. As the SEC explains in its investor bulletin on index funds, you cannot invest in an index itself, only in a fund that tracks it.

QQQ is the best-known Nasdaq 100 ETF. Invesco's QQQ overview confirms it tracks the Nasdaq-100 and is rebalanced quarterly and reconstituted once a year. QQQM follows the same index, so check each fund's official page for current fees before comparing them.

Some popular funds, like VTI, follow none of the three, so never assume. For the fee and trading differences between fund types, see our breakdown of index funds vs ETFs vs mutual funds.

How to check your fund's index in 4 steps

1. Search the ticker in your investing app and open the fund's page.
2. Find the "benchmark" or "index" line, usually on the overview tab or the fact sheet.
3. Check the holdings count: about 30 points to the Dow, about 500 to the S&P 500, about 100 to the Nasdaq-100.
4. Confirm on the fund provider's website or prospectus.

The same check works inside a retirement account. If you are opening one, our Roth IRA beginner's guide shows how to open one on an app.

Which index fits which goal?

None of these indexes is "the best." Each answers a different question, so match the index to what you want your money to do. This is education, not a recommendation to buy any fund.

• Broad exposure to large US companies: the S&P 500 is the usual starting point, which is why so many beginner core funds track it. A step-by-step Boredlisted guide to buying an S&P 500 index fund on an app is on the way.
• A tilt toward large growth and tech companies: the Nasdaq-100 is more concentrated, so it can climb faster in strong tech years and drop harder in weak ones.
• Following the daily headline: the Dow is useful context, but with 30 price-weighted stocks, few beginners make it their main holding.
• The whole US market, small companies included: none of the three. Look at total market funds instead.

You do not need a large balance to start with any of these. Our guide to investing with 100 dollars walks through getting started with a small amount on an app.

A quick note for UK readers: the FTSE 100

In the UK, the headline index is the FTSE 100, nicknamed the "Footsie." It holds the 100 largest eligible companies on the London Stock Exchange, ranked by market value and reviewed every quarter. Like the S&P 500, it gives bigger companies more weight.

UK investors can buy FTSE 100 trackers as well as UK-listed versions of S&P 500 and Nasdaq-100 funds. Many US-listed ETFs, including VOO and QQQ, are generally not offered to UK retail investors, so look for UK-listed UCITS versions (a European fund standard) on your platform. Holding them in a Stocks and Shares ISA keeps gains free of UK tax, and prices may be quoted in pounds (£) or dollars depending on the share class.