The term "annuity" refers to an insurance contract issued by financial institutions with the intention of paying out invested funds in a fixed income stream in the future. Investors invest in or purchase annuities with monthly premiums or lump-sum payments. The holding institution issues a stream of payments in the future for a specified period of time or for the remainder of the annuitant's life. Annuities are mainly used for retirement purposes and help individuals address the risk of outliving their savings.