What Is an Exchange-Traded Fund (ETF)?(by JAMES CHEN )

An exchange-traded fund (ETF) is a type of pooled investment security that operates much like a mutual fund. Typically, ETFs will track a particular index, sector, commodity, or other assets, but unlike mutual funds, ETFs can be purchased or sold on a stock exchange the same way that a regular stock can.

An ETF can be structured to track anything from the price of an individual commodity to a large and diverse collection of securities. ETFs can even be structured to track specific investment strategies.

The first ETF was the SPDR S&P 500 ETF (SPY), which tracks the S&P 500 Index, and which remains an actively traded ETF today.

KEY TAKEAWAYS

An exchange-traded fund (ETF) is a basket of securities that trades on an exchange just like a stock does.
ETF share prices fluctuate all day as the ETF is bought and sold; this is different from mutual funds, which only trade once a day after the market closes.1
ETFs can contain all types of investments, including stocks, commodities, or bonds; some offer U.S.-only holdings, while others are international.
ETFs offer low expense ratios and fewer broker commissions than buying the stocks individually.