What an ETF fund is

An ETF (exchange-traded fund) is a collection of investments bundled together and sold as a single security on a stock exchange. You buy and sell ETF shares the same way you buy and sell individual stocks — through a brokerage account, during market hours, at a price that changes throughout the day. Inside that one ETF share is a basket of many holdings: stocks, bonds, commodities, or a mix of those.

The key difference from a mutual fund is timing and price. A mutual fund's price is set once per day after the market closes. An ETF's price updates every few seconds while the market is open, just like a stock price does. This means you can trade an ETF at any moment during the trading day, not just at the end of it.

An ETF is managed by a fund company that decides what goes into the basket. Some ETFs track an index — a preset list of investments like the S&P 500 or the Nasdaq 100. Others are actively managed, meaning a fund manager picks and changes the holdings based on their strategy. You pay the fund company a fee (called an expense ratio) for managing the fund, usually expressed as a percentage of what you invest.

Key Takeaways

  • An ETF is a basket of investments you buy as a single share, traded on a stock exchange during market hours at a price that changes throughout the day.
  • Index ETFs track a preset list of investments and typically charge lower fees than actively managed ETFs or mutual funds.
  • You can buy an ETF through any brokerage account and hold it in a regular taxable account, a retirement account, or both.
  • ETFs are bought and sold at market price, which means you may pay more or less than the actual value of the holdings inside, though this gap is usually small.

How ETF holdings work

When you own an ETF share, you own a proportional stake in every holding inside that fund. If an ETF holds 500 stocks, you own a tiny piece of all 500. You do not own them directly — the fund company holds the actual securities — but you benefit from their performance.

The holdings inside an ETF depend on its strategy. A broad market ETF might hold hundreds of large U.S. companies. A sector ETF might hold only energy companies or technology companies. A bond ETF might hold government bonds, corporate bonds, or both. A commodity ETF might track the price of gold, oil, or agricultural products. Some ETFs mix stocks and bonds together in a single fund.

If the fund is index-based, the holdings are determined by the index it tracks. The fund company straightforward buys whatever is in that index and rebalances when the index changes. If the fund is actively managed, a fund manager decides which securities to buy and sell based on their research and strategy. Active management typically costs more in fees.

ETF fees and expenses

The main cost of owning an ETF is the expense ratio, a yearly fee expressed as a percentage of your investment. An ETF with a 0.05% expense ratio costs $5 per year for every $10,000 you invest. An ETF with a 1% expense ratio costs $100 per year on the same $10,000.

Index ETFs typically charge lower expense ratios — often between 0.03% and 0.20% — because they straightforward track a list and do not require active management. Actively managed ETFs usually charge more, often between 0.50% and 1.50% or higher, because a manager is making decisions about what to buy and sell.

Beyond the expense ratio, you may pay a trading commission when you buy or sell an ETF share, depending on your brokerage. Many brokerages now offer commission-free ETF trading, but some still charge a small fee per trade. You should check your brokerage's fee schedule before you trade.

If an ETF pays dividends or interest from its holdings, you receive that income. You may owe taxes on those distributions in the year you receive them, even if you reinvest them back into the fund. This tax treatment depends on whether you hold the ETF in a taxable account or a tax-advantaged retirement account.

ETFs versus mutual funds

Both ETFs and mutual funds hold baskets of investments, but they work differently in three main ways: price, trading, and taxes.

A mutual fund's price is calculated once per day after the market closes. You place an order to buy or sell at any time during the day, but you do not know the exact price until after 4 p.m. Eastern Time. An ETF's price is set by supply and demand on the exchange throughout the trading day, so you see the price before you buy and can trade at any moment the market is open.

Mutual funds are bought and sold directly through the fund company or a brokerage. ETFs are bought and sold on a stock exchange like any stock. This makes ETFs more flexible if you want to trade quickly or set a specific price limit on your order.

ETFs are generally more tax-efficient than mutual funds. The way ETFs are structured allows fund companies to avoid distributing capital gains to shareholders as often, which means you may owe less in taxes each year. Mutual funds distribute capital gains more frequently, which can create a tax bill even in years when the fund's value goes down.

How to buy and hold an ETF

You buy an ETF through a brokerage account — the same type of account you would use to buy individual stocks. Open an account with a brokerage, deposit money, search for the ETF by its ticker symbol (a short code like SPY or VOO), and place a buy order. You can set the order to execute at market price (the current price) or set a limit price (the maximum you are willing to pay).

Once you own the ETF, it sits in your account and you can hold it as long as you want. You can sell it at any time during market hours. You can also hold an ETF inside a retirement account — a traditional IRA, Roth IRA, 401(k), or other tax-advantaged account — where the tax rules are different.

ETFs can be held in a regular taxable brokerage account, where you owe taxes on dividends and capital gains each year. They can also be held in a retirement account, where taxes are deferred or eliminated depending on the account type. Many people use ETFs as the core holdings in both types of accounts because of their low fees and flexibility.

The difference between ETF price and net asset value

Every ETF has a net asset value (NAV), which is the total value of all the holdings inside the fund divided by the number of shares outstanding. This is the true value of what you own. The market price of an ETF is what buyers and sellers are willing to pay for it on the exchange at any given moment.

Most of the time, the market price and the NAV are very close — within a few cents. But they can diverge slightly. If more people want to buy the ETF than sell it, the market price may rise above the NAV. If more people want to sell than buy, the market price may fall below the NAV. This difference is called a premium (price above NAV) or discount (price below NAV).

For most ETFs, especially large, popular ones, this gap is tiny and closes quickly. For smaller or less-traded ETFs, the gap can be larger and last longer. This is one reason to check the trading volume and bid-ask spread (the difference between the highest price a buyer will pay and the lowest price a seller will accept) before buying an ETF with low trading activity.

Types of ETFs and their strategies

ETFs come in many varieties based on what they hold and how they work. Stock ETFs hold shares of companies and track indexes like the S&P 500, Nasdaq 100, or specific sectors like technology or healthcare. Bond ETFs hold government or corporate bonds and track bond indexes. Commodity ETFs track the price of physical goods like gold, oil, or wheat.

Some ETFs use leverage, meaning they use borrowed money or derivatives to try to amplify returns. A 2x leveraged ETF aims to move twice as much as its underlying index. These are riskier and are designed for short-term trading, not long-term holding.

Inverse ETFs are designed to move in the opposite direction of their underlying index — they go up when the market goes down. Like leveraged ETFs, these are tactical tools for experienced traders, not core holdings for long-term investors.

International ETFs hold stocks or bonds from outside the United States. Dividend ETFs focus on companies that pay high dividends. Factor ETFs target stocks with specific characteristics like low price-to-earnings ratios or high momentum. The variety is large, and the strategy behind each one shapes what you should expect from it.

Frequently Asked Questions

Do I own the actual stocks or bonds inside an ETF?

No, you own shares of the ETF, not the underlying securities directly. The fund company holds the actual stocks or bonds. You benefit from their performance and receive dividends or interest, but you do not have direct ownership or voting rights in the individual companies.

Can I lose money in an ETF?

Yes. If the value of the holdings inside the ETF goes down, the value of your ETF shares goes down too. ETFs are not may provide investments. The amount you can lose is limited to what you invested, unless you use leverage or margin, which can amplify losses.

What is the difference between an ETF and a stock?

A stock is a share of ownership in a single company. An ETF is a basket of many investments bundled together. When you buy a stock, you own a piece of that one company. When you buy an ETF, you own a piece of many companies (or bonds, or commodities) at once. ETFs provide when ready diversification; stocks do not.

How often should I check my ETF holdings?

That depends on your strategy. If you are holding an ETF for the long term, checking once or twice a year is enough. If you are trading actively, you may check daily or more often. Most fund companies publish holdings information on their websites, and many update it daily or weekly.

Can I buy an ETF in a retirement account?

Yes. Most brokerages allow you to buy ETFs inside IRAs, 401(k)s, and other retirement accounts. The tax treatment depends on the account type — in a traditional IRA or 401(k), taxes are deferred; in a Roth IRA, may have access to withdrawals are tax-free. ETFs are popular retirement account holdings because of their low fees and flexibility.