What Is a Fixed-Income Security?A fixed-income security is an investment that provides a return in the form of fixed periodic interest payments and the eventual return of principal at maturity. Unlike variable-income securities, where payments change based on some underlying measure—such as short-term interest rates—the payments of a fixed-income security are known in advance.KEY TAKEAWAYSFixed-Income security provides investors with a stream of fixed periodic interest payments and the eventu...