Exchange-Traded FundETF
An exchange-traded fund is a fund whose shares trade on an exchange like a stock. Most ETFs track an index, sector or commodity, giving broad exposure in a single trade.
An ETF lets you buy a whole basket of assets — hundreds of shares, a sector, bonds or a commodity — in one trade, at a price that updates all day like a stock. That combination of diversification, low cost and easy trading has made ETFs one of the most popular products for investors and traders alike. This entry explains how ETFs work, what they cost, and the special risks of leveraged and inverse ETFs.
- Category
- Trading Basics
- Reading time
- 4 min
- Also called
- Exchange-traded product, Leveraged ETF, Inverse ETF
- Updated
An ETF in plain words
An ETF is a fund split into shares that trade on an exchange.1 Buy one share of an index ETF and you own a small slice of every company in that index. See Diversification.
The fund charges a yearly fee, the expense ratio, taken out of its assets. You also pay the usual trading costs when you buy and sell. See Trading Fees and Commissions.
How to evaluate an ETF, step by step
Check what it tracks
The index, sector or asset, and how closely it follows it.
Check the cost
The expense ratio, plus the bid–ask spread. See Bid-Ask Spread.
Check liquidity
Trading volume and the liquidity of the underlying assets. See Liquidity.
Check the structure
Physical (holds the assets) or synthetic (uses derivatives); leveraged or not.
Check the tracking difference
How far its return has differed from the index over time.
Understand taxes and domicile
Where the fund is based affects tax treatment and availability.
Worked examples
Example 1 — One trade, broad exposure
DiversifiedInstead of buying 500 shares separately, an investor buys $5,000 of an ETF tracking a 500-stock index.
| Holdings | Small stakes in all 500 companies |
| Trades needed | 1 |
ETFs make diversification simple and cheap.
Example 2 — Cost over time
Fees$20,000 invested for 10 years in two similar ETFs, one charging 0.05% a year, one 0.75%.
| Approx. fees, cheap ETF | ≈ $100 total |
| Approx. fees, expensive ETF | ≈ $1,500 total |
Small percentage differences add up over years (ignoring growth, which widens the gap further).
Example 3 — Leveraged ETF decay
DecayAn index goes +10% then −10%. A 2× daily leveraged ETF goes +20% then −20%.
| Index after two days | 100 → 110 → 99 (−1%) |
| 2× ETF after two days | 100 → 120 → 96 (−4%) |
Daily resets make leveraged ETFs lose value in choppy markets.2 They are built for short holding periods.
ETF vs. other ways to invest
| Aspect | ETF | Mutual fund | Single stock |
|---|---|---|---|
| Diversification | Broad | Broad | None |
| Trading | All day on an exchange | Once a day at a set price | All day on an exchange |
| Typical costs | Often low | Often higher | Trading costs only |
| Company-specific risk | Low | Low | High |
How ETFs are used
Core investing
Low-cost index exposure for the long term.
Sector bets
Trading a whole industry instead of picking one company.
Hedging
Shorting an index ETF to offset stock positions. See Hedging.
Access
Bonds, commodities or foreign markets in one product.
Advantages and disadvantages
Advantages
- Instant diversification in one trade.
- Usually low ongoing costs.
- Trades all day like a stock.
- Transparent holdings for most funds.
Disadvantages
- Leveraged and inverse ETFs decay over time.
- Thinly traded ETFs can have wide spreads.
- Tracking can differ from the index.
- Easy trading can encourage overtrading.
Going deeper
Read as far as you need. Each level builds on the one before it.
ETF price vs. holdings value
Beginner
Specialised firms create and redeem ETF shares, which keeps the ETF’s price close to the value of what it holds.
Tracking difference
Intermediate
Fees, cash holdings and trading costs mean an ETF’s return differs slightly from its index. Compare funds on their actual tracking record, not just the fee.
Synthetic ETFs
Advanced
Some ETFs replicate an index with swaps instead of owning the assets. This adds counterparty risk, managed through collateral.
Common mistakes
Holding leveraged ETFs long-term
They are designed for daily targets.
Ignoring spreads
Check the bid–ask spread, not only the fee.
Owning overlapping ETFs
Several funds may hold the same big companies.
Market orders at the open
Spreads are often wider early in the session.
Check your understanding
Test yourself before moving on. Each answer comes with an explanation.
Key points to remember
- An ETF is a fund that trades on an exchange like a stock.
- Most track an index, giving broad exposure in one trade.
- Compare expense ratio, spread and tracking difference.
- Leveraged and inverse ETFs reset daily and decay over time.
- Check overlap between funds you hold.
Frequently asked questions
Is an ETF safer than a stock?
Do ETFs pay dividends?
Can I hold a leveraged ETF for months?
Further learning
- Diversification
Why owning a basket reduces risk.
- Leverage
What leveraged ETFs are built on.
- Bid-Ask Spread
A cost to check before trading any ETF.
- Hedging
Using index ETFs to offset risk.
Sources
This article is written in our own words. The sources below support the specific facts, rules and figures marked with a number in the text. Links open the original publisher’s page.
- Investor.gov (SEC). Updated Investor Bulletin: Exchange-Traded Funds (ETFs) (opens in a new tab) Checked .
- Investor.gov (SEC). Leveraged Investing Strategies – Know the Risks Before Using These Advanced Investment Tools (opens in a new tab) Checked .
Educational content, not financial advice. Examples use hypothetical prices and simplified costs; actual fees, margin rules and regulations vary by broker, market and country. We are not affiliated with any publisher linked above. Last reviewed . Report an error or request a source credit.