An exchange-traded fund (ETF) contains investments organized around a strategy, exposure, or theme. The approach might do one of the following: Track a sector of the stock market, such as energy or technology. Invest in a certain type of bond, such as municipal or high-yield. Track a market index, such as the NASDAQ composite index or S&P 500. An ETF trades on exchanges. The price fluctuates throughout the day, and the fund is liquid and flexible. How Does an Exchange-Tra