The value of a convertible bond (CB) without its conversion feature, i.e., only as a straight bond. The investment value represents a lower theoretical bound to the price of a convertible bond (in other words, it the floor under which the bond should not trade). The investment value of a convertible is affected by changes in interest rates and the fundamentals of the issuer, and therefore bond flows are discounted at the issuer’s cost of debt.

It is also known as bond value.