An ETF is a fund that holds many stocks or bonds and trades like a single stock

ETF stands for exchange-traded fund. It is a basket of investments — usually stocks, bonds, or a mix — bundled together and sold as one unit on a stock exchange. You buy and sell it the same way you would buy and sell a single company's stock: through a brokerage account, during market hours, at a price that changes throughout the day.

The main difference between an ETF and buying individual stocks is that one ETF holding gives you exposure to dozens, hundreds, or even thousands of investments at once. For example, an S&P 500 ETF holds shares in 500 large U.S. companies. A bond ETF might hold hundreds of different bonds. You own a small piece of each one without having to buy them separately.

Key Takeaways

  • An ETF is a collection of stocks, bonds, or other investments packaged as a single security that trades on a stock exchange during market hours.
  • You can buy and sell ETF shares through a brokerage account the same way you would buy individual stocks, and the price changes throughout the day.
  • ETFs typically charge lower fees than actively managed mutual funds because most are designed to track an index rather than be managed by a person making buy-and-sell decisions.
  • Diversification happens automatically — one ETF holding gives you exposure to many investments, which reduces the risk of any single investment hurting your overall portfolio.

How an ETF differs from a mutual fund

Both ETFs and mutual funds hold baskets of investments, but they work differently in practice. A mutual fund is priced once per day, after the market closes. You place an order during the day, but you do not know the exact price until the end of trading. An ETF is priced continuously throughout the day, just like a stock, so you see the price in real time and can buy or sell whenever the market is open.

Mutual funds are often actively managed, meaning a fund manager decides which investments to buy and sell to try to beat the market. That active management costs money — mutual funds typically charge higher fees. Most ETFs are passively managed, meaning they simply track an index (like the S&P 500 or the Nasdaq 100) and hold the same investments in the same proportions. Lower fees make ETFs cheaper to own over time.

You can also buy and sell mutual funds only through the fund company itself or through a broker. ETFs trade on exchanges like the New York Stock Exchange, so you have more flexibility in when and how you trade them.

What types of ETFs exist

ETFs come in many varieties depending on what they hold and what they aim to do. Stock ETFs hold shares in companies and track indexes like the S&P 500, the Nasdaq 100, or specific sectors (technology, healthcare, energy). Bond ETFs hold government or corporate bonds and give you exposure to fixed income. Commodity ETFs track the price of oil, gold, or agricultural products. International ETFs hold stocks or bonds from outside the United States.

Some ETFs are very broad — a total U.S. stock market ETF holds thousands of companies. Others are narrow — a semiconductor ETF holds only companies that make computer chips. Some ETFs use leverage or inverse strategies to try to amplify gains or profit when prices fall, though these are riskier and meant for experienced investors.

There are also thematic ETFs that focus on trends like renewable energy, artificial intelligence, or cybersecurity. The number of ETFs has grown rapidly; there are now thousands to choose from, so it is worth understanding what each one holds before you buy.

How fees work with ETFs

When you own an ETF, you pay an annual fee called an expense ratio. This is a percentage of your investment that goes to cover the fund's operating costs. For a passively managed ETF that simply tracks an index, the expense ratio is typically very low — often between 0.03% and 0.20% per year. That means if you own $10,000 in an ETF with a 0.10% expense ratio, you pay about $10 per year.

Actively managed ETFs, which have a manager making investment decisions, charge higher fees — often 0.50% to 1.00% or more. You also pay a brokerage commission when you buy or sell, though many brokerages now offer commission-free ETF trading. Some ETFs also distribute dividends or capital gains to shareholders, which may trigger taxes if you hold them in a regular (non-retirement) account.

Why people use ETFs for diversification

One of the biggest reasons to own an ETF is instant diversification. If you buy a single stock and that company struggles, your investment takes a big hit. If you own an ETF holding 500 stocks and one company struggles, the impact on your overall holding is tiny. This spreading of risk across many investments is called diversification, and it is one of the most reliable ways to reduce the damage from any single bad investment.

You can build a diversified portfolio with just a handful of ETFs. For example, you might own a U.S. stock ETF, an international stock ETF, and a bond ETF. Together, these three holdings give you exposure to thousands of investments across different countries and asset types. Doing the same thing with individual stocks would require buying hundreds of them and tracking each one separately.

How to buy an ETF

To buy an ETF, you need a brokerage account with a company like Fidelity, Charles Schwab, Vanguard, E-Trade, or many others. Open an account, fund it with money, and then search for the ETF you want by its ticker symbol (a short code like SPY for the S&P 500 ETF or QQQ for the Nasdaq 100 ETF). Place a buy order just as you would for a stock, and the shares will settle in your account within two business days.

You can hold ETFs in a regular taxable brokerage account or in a retirement account like an IRA or 401(k). Many people use ETFs as the core of their retirement savings because the low fees and broad diversification make them well-suited to long-term holding. You can also set up automatic monthly investments in ETFs, which is a simple way to build wealth over time without having to time the market.

Frequently Asked Questions

Can I lose money in an ETF?

Yes. If the stocks or bonds the ETF holds fall in value, your ETF shares will fall too. Diversification reduces risk but does not eliminate it. A broad stock market ETF is less risky than owning a single stock, but it can still lose 20%, 30%, or more in a bad market year. Bond ETFs can also lose value if interest rates rise.

Do I have to hold an ETF for a certain amount of time?

No. You can buy and sell ETF shares whenever the market is open, with no minimum holding period. However, if you are investing for retirement or a long-term goal, frequent trading can trigger taxes and fees that eat into your returns. Most people buy ETFs and hold them for years or decades.

What is the difference between an ETF and an index fund?

An index fund is a type of mutual fund or ETF that tracks an index. So all index funds are either mutual funds or ETFs, but not all ETFs are index funds — some are actively managed. The key difference is how they trade: index mutual funds are priced once per day, while index ETFs trade throughout the day like stocks.

How many ETFs should I own?

There is no single right answer, but most financial advisors suggest that three to seven ETFs are enough to build a well-diversified portfolio. Owning too many can make your portfolio harder to track and may create overlap (holding the same companies in multiple ETFs). A simple approach is one U.S. stock ETF, one international stock ETF, and one bond ETF.