Mutual fund
A fund that pools money from many investors to buy stocks, bonds or other assets, priced once a day after the market closes.
When you buy a mutual fund, you own a share of everything it holds. Orders are filled at the end of the trading day at a price called the net asset value.
Some mutual funds are index funds. Others are actively managed, where managers pick investments and often charge more. Some have minimum investments or sales fees, so check the costs first. Mutual funds are common choices inside 401(k) plans.