You’ve probably seen the word “Nasdaq” in the news. But it doesn’t always mean the same thing. Sometimes it means a stock exchange, a place where people buy and sell shares. Sometimes it means an index, which is just a number used to track how a group of stocks is doing.

This mix-up happens a lot, and it matters if you’re trying to follow financial markets with any real understanding. A news headline might say “Nasdaq fell today,” but it may not tell you which Nasdaq it means. Here’s what each one actually refers to, what the two main indexes track, and what makes prices move.

Nasdaq Is Actually a Few Different Things

First, there’s the Nasdaq Stock Market. This is a real stock exchange, a marketplace where shares of companies are bought and sold. It launched in 1971 as the world’s first electronic stock market. Thousands of companies have securities listed on the exchange today, in fields like tech, health care, retail, and banking.

Then there are the indexes. An index is not a company or a place. It’s a number that adds up how a group of stocks is doing, so people can see the bigger picture at a glance.

The Nasdaq Composite is one of these indexes. It tracks more than 3,000 eligible securities listed on the Nasdaq Stock Market, giving a broad view of the companies traded there. A security generally needs to be listed exclusively on Nasdaq to qualify, and it needs to be a common stock, an ADR, or a similar equity type; things like ETFs and preferred shares aren’t included.

The Nasdaq-100 is a smaller, different index. It tracks 100 of the largest eligible non-financial companies listed on Nasdaq, which means banks, insurers, and other financial companies are left out.

There’s also Nasdaq, Inc., the company behind the Nasdaq Stock Market and a broader business that provides market technology, data, and financial infrastructure services. When you read that “Nasdaq had strong earnings,” that usually means Nasdaq the company, not the index.

So a company can be listed on Nasdaq without being part of the Nasdaq-100. And the Composite and the Nasdaq-100 can move in different directions on the same day, because they track different groups of stocks. Once you understand these four meanings, Nasdaq news is much easier to follow.

What Does “Nasdaq” Actually Mean in the News?

This is where most of the confusion starts. When a headline says “Nasdaq fell 2% today,” it’s rarely talking about the exchange itself, since an exchange doesn’t rise or fall the way a number does. It’s talking about one of the indexes.

The problem is that different publications use the word “Nasdaq” to mean different things. Some are referring to the Nasdaq Composite, which is the broader Nasdaq market benchmark. Others mean the Nasdaq-100, especially when the story is about large, well-known technology companies. A few use “Nasdaq” loosely to mean Nasdaq-listed stocks in general, without pointing to either specific index.

The safest habit is to check which index a headline or chart is actually citing before assuming you know what moved. A 2% drop in the Composite and a 2% drop in the Nasdaq-100 can be driven by very different companies, even on the same day.

The Nasdaq Composite, Explained Simply

The Nasdaq Composite started in 1971, at the same time as the exchange itself. It’s meant to give a broad, big-picture view of the Nasdaq exchange.

People often call the Composite a “tech index,” but that’s not quite right. Yes, tech companies make up a big part of it, mostly because so many large tech firms chose to list on Nasdaq. But the Composite also includes health care companies, retailers, banks, and more.

The index is market-cap weighted, meaning bigger companies have more influence on its performance than smaller ones. Unlike the Nasdaq-100, the Composite uses each company’s full listed market value, with no float adjustment or concentration cap on the influence of individual companies.

The Nasdaq-100, Explained Simply

The Nasdaq-100 started later, on January 31, 1985. The idea was to build an index around the largest eligible non-financial companies on Nasdaq. The Nasdaq-100 is also tracked by investment products such as QQQ, an ETF designed to follow the index.

Two rules make this index different from the Composite. First, banks, insurance firms, and other financial companies are left out completely. Second, being big alone isn’t enough to join. Nasdaq applies eligibility and trading requirements, with an annual reconstitution in December and quarterly rebalances in between.

It uses a modified market-capitalization weighting method with concentration controls that limit the influence of the largest companies. Even with those controls, tech companies still make up a large share of the Nasdaq-100.

One thing to remember: the Nasdaq-100 is not the whole Nasdaq market. It leaves out thousands of smaller companies and every financial firm. Because of this, it can perform quite differently from the Composite.

Nasdaq Composite vs. Nasdaq-100

Feature	Nasdaq Composite	Nasdaq-100
What it covers	Broad Nasdaq-listed equity securities	100 large eligible non-financial Nasdaq companies
Roughly how many securities	More than 3,000 securities	About 100
Includes financial companies?	Yes	No
Started	1971	1985
How it’s weighted	Market-cap weighted	Modified market-cap weighted
What it helps measure	Broad Nasdaq-listed equity market	Large non-financial Nasdaq companies

The two indexes share many of the same big companies, since the largest Nasdaq firms usually appear in both. But they answer different questions. Want to know how the whole Nasdaq market is doing? Look at the Composite. Want to know how the biggest Nasdaq companies are doing? Look at the Nasdaq-100.

Why People Think of Nasdaq as a “Tech Exchange”

Nasdaq has a strong link to technology because many large technology companies have listed there over the years, and those companies now carry substantial weight in its major indexes.

Still, Nasdaq is not only tech. Both indexes have significant exposure to technology, while also including companies from other sectors. It’s more accurate to say Nasdaq is a major stock market with heavy technology and growth exposure, not a tech-only market.

How the Nasdaq Exchange Works

Nasdaq operates as an electronic marketplace rather than a traditional physical trading floor. When you place an order through a broker, that order enters the market, where it can be matched with available liquidity according to the order type and market conditions.

Nasdaq also uses market makers. These are firms that provide liquidity by standing ready to buy or sell certain securities under specified market conditions. This helps trades happen smoothly, even if a buyer and a seller aren’t both ready at the exact same moment.

Nasdaq itself doesn’t decide what a stock is worth. Prices move because of buyers and sellers, not because the exchange sets a price. Nasdaq’s job is to run the marketplace where that buying and selling happens. Companies seeking a Nasdaq listing must also meet applicable financial, liquidity, and corporate governance requirements before their shares can trade there.

What Makes Nasdaq Go Up or Down

No single thing explains every move in Nasdaq. A few things tend to matter most.

Interest rates. When it gets more expensive to borrow money, investors often become more careful about paying high prices for companies expected to grow a lot in the future. This can hit fast-growing Nasdaq companies harder than steadier ones. This isn’t a strict rule that always happens, but it’s a pattern that shows up often.

Company earnings. Strong earnings can support a stock price, especially when results beat what investors were already expecting. Weak results or cautious guidance can have the opposite effect. Because big companies carry more weight, their earnings can move the whole index.

Economic news. Reports on prices, jobs, and spending shape what investors expect will happen with interest rates and company profits next.

How investors feel. When people feel confident, they’re often willing to pay more for growing companies. When confidence drops, those same stocks can lose value quickly, sometimes faster than the actual business has changed.

These things don’t happen alone. They often feed into each other. That’s why it’s worth looking past a single day’s number and asking what’s really behind it.

How to Read Nasdaq Numbers

When you look up Nasdaq, you’ll usually see three things: the index level, the daily change, and trading volume.

The index level is just the current value of the index. On its own, it doesn’t mean much. It’s more useful to compare it with where it was before.

The daily change shows how much the index moved since the last trading day, usually as a percentage. A gain of 1% means it closed 1% higher than the day before.

Trading volume shows how many shares changed hands. A large price move alongside high volume shows that substantial trading activity took place. Volume alone doesn’t explain why the price moved. It tells you how much trading activity occurred.

It also helps to look beyond just one day. Checking how the index did over weeks, months, or years gives a much clearer picture than a single day’s number.

How to Invest in Nasdaq

You can’t buy an index itself. Investors can instead buy individual Nasdaq-listed stocks or investment products designed to track a Nasdaq index.

One way to get index exposure is through an ETF, a fund designed to track an index such as the Nasdaq-100. Instead of buying the individual securities yourself, you buy shares of the fund, which does the tracking for you. It’s worth checking exactly which index a fund follows before buying it, since a “Nasdaq” fund could track the Composite, the Nasdaq-100, or something more specific, and these can perform very differently.

You can also buy individual Nasdaq-listed stocks directly. This gives you more control, but also more risk, since your money isn’t spread across many companies.

If you’re investing from outside the United States, a few extra things matter too, like currency exchange rates, local taxes, and whether your broker even offers the product you want.

Nasdaq vs. S&P 500 vs. Dow Jones

Index	What it covers	Number of companies	How it’s weighted
Nasdaq Composite	Broad Nasdaq-listed equity securities	More than 3,000	Market-cap weighted
Nasdaq-100	Largest eligible non-financial Nasdaq companies	About 100	Modified market-cap weighted
S&P 500	Large-cap U.S. companies meeting S&P’s eligibility criteria	500	Market-cap weighted
Dow Jones	30 major U.S. companies	30	Price weighted

These indexes are built in different ways, and that matters. The S&P 500 isn’t a Nasdaq index at all. It’s a separate large-cap U.S. equity index with its own eligibility and selection rules, and it uses float-adjusted market-cap weighting. The Dow Jones is a long-running index of 30 major U.S. companies that uses a price-weighted methodology instead: a stock with a higher share price moves the Dow more, even if the company itself isn’t bigger.

No single index tells you everything about the stock market. The Nasdaq Composite and Nasdaq-100 have significant exposure to technology and other growth-oriented companies, the S&P 500 gives a broader view of large-cap U.S. companies, and the Dow offers a narrower, differently weighted view built around 30 names.

Risks to Know About

Putting money into Nasdaq stocks or funds carries the same basic risk as any stock investment: prices can go down as well as up, and past results don’t guarantee future ones.

A few risks are more specific to Nasdaq. Because the indexes are weighted by size, a small number of huge companies can have a big effect on the whole index, in good times and bad. Company prices can also get ahead of themselves. A healthy, profitable company can still see its stock price drop if investors expected even more growth than it delivered. And because many Nasdaq companies are tied to fast-changing industries like tech, prices can swing quickly when earnings, economic news, or interest rate expectations change.

Before buying anything linked to Nasdaq, it helps to know exactly which index it follows, what fees it charges, and how many different companies it actually holds.

The Bottom Line

Once you know the difference between the Nasdaq exchange, the Nasdaq Composite, and the Nasdaq-100, the daily headlines make a lot more sense. “Nasdaq is up today” doesn’t tell you much on its own. Knowing which index moved, and which companies drove it, does.

Frequently Asked Questions

Does the S&P 500 or the Dow Jones include Nasdaq companies? Yes. Both can include companies that happen to be listed on Nasdaq, since they draw from the broader U.S. market rather than from a single exchange. A company can appear in the S&P 500 or the Dow and still be part of the Nasdaq Composite or Nasdaq-100 at the same time.

Why do funds with “Nasdaq” in the name sometimes perform so differently from each other? Because they can track different indexes. One fund might follow the Composite, another the Nasdaq-100, and a third a narrower sector slice. Always check which specific index a fund tracks before comparing returns.

Is a bigger Nasdaq company always a bigger part of the index? Generally, yes. The Composite is market-cap weighted, so larger companies have greater influence on its value. The Nasdaq-100 also weights by size but applies concentration controls that limit how much influence the largest names can have.

How is the Nasdaq-100 different from just picking the 100 biggest Nasdaq companies? It excludes financial companies entirely and applies its own eligibility and trading requirements rather than ranking purely by market value. Its makeup is set through an annual reconstitution in December, with quarterly rebalances in between.

Can trading volume tell me which way a stock will move next? Not on its own. High volume shows more shares changed hands during a move, which can suggest strong interest, but it doesn’t by itself explain why the price moved or predict what happens next.