An exchange-traded fund (ETF) is an investment fund that trades on an exchange like a stock, with prices fluctuating throughout the trading day based on supply and demand. Most ETFs track an index (S&P 500, Bloomberg US Aggregate Bond Index, etc.) and use a passive management strategy, resulting in very low expense ratios. Unlike mutual funds, ETF shares are not purchased from or redeemed with the fund directly by retail investors — they are bought and sold in the secondary market.
The creation/redemption mechanism involving authorized participants (APs) — large broker-dealers — keeps ETF prices aligned with NAV. APs can create new ETF shares by depositing a basket of underlying securities (creation), or redeem ETF shares by exchanging them for the underlying basket (redemption). This arbitrage mechanism prevents persistent large premiums or discounts.
ETFs offer significant tax efficiency compared to mutual funds. The in-kind creation/redemption process means the fund rarely needs to sell securities to meet redemptions, limiting capital gain distributions. Investors control when they realize capital gains by choosing when to sell their shares.
ETFs can be traded on margin, sold short, and optioned — just like individual stocks. They offer intraday liquidity, transparency (most disclose holdings daily), and can be bought through any brokerage account.
> Exam tip: On the Series 7 and Series 65/66, understand the creation/redemption arbitrage mechanism that keeps ETF prices close to NAV. Know that ETFs can trade at a premium or discount to NAV (unlike mutual funds which always transact at NAV). ETFs are generally more tax-efficient than equivalent mutual funds. The SIE and Series 6 exams focus on the basic structure and how ETFs differ from mutual funds.