An ETF is a basket of investments — often hundreds of stocks or bonds — that trades on an exchange like a single share. Buy one share of an S&P 500 ETF and you effectively own a slice of the 500 largest US public companies.
What an ETF is
An ETF issuer buys a portfolio of assets and issues shares against it. Those shares trade throughout the day at prices set by supply and demand, kept close to the underlying value by "authorised participants" who arbitrage discrepancies.
ETF vs mutual fund
- Trading: ETFs trade continuously; mutual funds price once at market close.
- Fees: Passive ETFs are typically much cheaper than actively managed mutual funds.
- Taxes: ETFs are generally more tax-efficient in taxable accounts due to their creation/redemption mechanism.
- Minimums: ETFs let you buy a single share; many mutual funds require $1,000+.
Common types of ETFs
- Broad index — S&P 500, total US market, total world market.
- Sector — tech, healthcare, energy.
- Bond — treasuries, corporates, municipals.
- Thematic — AI, clean energy, cybersecurity.
- Dividend / factor — high yield, low volatility, value, quality.
- Leveraged and inverse — 2× or −1× daily returns. Not buy-and-hold.
How to choose one
- Expense ratio — every basis point compounds. Broad index ETFs cost 0.03–0.10%.
- Assets under management — larger funds are usually more liquid and less likely to close.
- Tracking difference — how closely the fund matches its index over time.
- Underlying holdings — read the top 10; some "diversified" ETFs are actually concentrated.
Risks and misconceptions
Frequently asked questions
Are ETFs safe?
Diversified index ETFs are generally lower risk than owning a handful of individual stocks, because a single company's collapse barely moves the fund. But the underlying assets still fluctuate — an S&P 500 ETF fell 20% in 2022.
What's the difference between VOO, SPY, and IVV?
All three track the S&P 500. They differ in expense ratio and issuer. VOO (Vanguard) and IVV (iShares) are cheaper than SPY (State Street), but SPY has the highest trading volume, which matters for very short-term traders.
Do ETFs pay dividends?
Yes. ETFs that hold dividend-paying stocks pass through dividends to shareholders, usually quarterly. Some ETFs automatically reinvest; others distribute cash.
Put this into practice
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