Oct 31, 2024 · What is an ETF? An ETF is a tradeable fund, containing many investments, generally organized around a strategy, theme, or exposure. That approach could be tracking a sector of the stock market, like technology or energy; investing in a specific type of bond, like high-yield or municipal; or tracking a market index, like the S&P 500 ® 1 or Nasdaq composite index. 2 Unlike mutual funds, ETFs ...