If the coupon interest rate is 4.375% for the first six months and changes to a rate equal to the 10-year treasury bond rate plus 1.3% thereafter, the bond is called afloating-rate bond. the contract that describes the terms of a borrowing arrangement between a firm that sells a bond issue and the investors who purchase the bonds is called the . when are issuers more likely to call an outstanding bond issue? when interest rates are lower than they were when the bonds were issued when interest rates are higher than they were when the bonds were issued.