What is an ETF?

What an exchange-traded fund is, how ETFs differ from mutual funds and single stocks, the main types of ETF, and what to check before buying one.

A basket you can trade

An ETF is a fund that holds a basket of investments and trades on an exchange like a single stock. One share of an S&P 500 ETF gives you a slice of all 500 companies.

ETFs versus mutual funds

ETF Mutual fund
Trading Any time the market is open Once a day at the closing price
Minimum One share or less Often $1,000 or more
Costs Usually low Varies, often higher
Taxes Usually fewer capital gains payouts More payouts

Types of ETF

  • Broad index: the whole market or a big index. See Index funds.
  • Sector and theme: technology, healthcare, clean energy.
  • Bond: Treasuries, corporate bonds.
  • Leveraged and inverse: 2x or 3x daily moves, or the opposite. Very different risks: see Leveraged ETFs explained and Inverse ETFs.

What to check

  1. What it holds and how it chooses holdings.
  2. The expense ratio.
  3. Size and trading volume, so the spread is tight.
  4. Whether it is really an ETN. See ETF vs ETN.

See also

Pages that link here: Building your investing knowledge, Investing FAQ

Last updated September 30, 2026. Education only, not investment advice.