A study found that people's minds wander an average of 15-20% of the time, even when reading. The study had students record their thoughts at random times throughout the day. A mutual fund is an investment company that collects money from shareholders to purchase a portfolio of securities like stocks and bonds. Shareholders own shares of the fund and can make or lose money from rises and falls in the value of the securities held by the fund. There are three main types of mutual funds - stock funds that invest in company shares, bond funds that invest in bonds, and money market funds that invest in short-term securities.