The term structure of interest rates is the relationship between interest rates or bond yields and different terms or maturities. As demand for bonds increases, so do bond prices and bondholder returns.The many different kinds of bonds. A new report from Moody's published in midMarch shows increasing numbers of issuers are turning to sustainable bonds to support gender equality goals. In the case of bonds, investors should understand that the bond market isn't always instantly liquid, and some bonds are easier to trade than others.