♪ [music] ♪ - [Narrator] What is a mutual fund? Rather than picking a particular stock, many people invest in the stock market by buying a mutual fund, a portfolio of assets like stocks and bonds managed by professionals for a management fee. There are thousands of mutual funds, but we can broadly break them into two types -- actively managed and passively managed. As its name suggests, actively managed funds are actively managed. Experts pick stocks and bonds and charge fees. Passive mutual funds, on the other hand, aren't actively managed. No one is trying to pick winners or avoid losers. Passive mutual funds are simply an investment portfolio of a big basket of stocks, such as the S&P 500, which is a basket of 500 large stocks that represent the U.S. economy. The fees for a passive fund are much lower than an active fund, since no expert is actively managing the fund. ♪ [music] ♪ To learn more about investing, click here. Or, to test your knowledge on mutual funds, click here. ♪ [music] ♪ Still here? Check out Marginal Revolution University's other popular videos. ♪ [music] ♪