You should receive and review a prospectus before investing. The prospectus usually tells you how well the fund has performed in the past. This information can give you an idea about what you might earn on your investment. As with all investments, however, past performance is no guarantee of future result. All investments carry some risk, including loss of principal.
Banks use different arrangements to sell mutual funds.
Some banks simply rent space in bank lobbies to outside companies. Other banks sell proprietary funds. These funds are sponsored by an outside entity. The bank then advises the fund about what investments to make. It receives a fee from the fund for that service.