Bond valuation is the act of determining the fair price of a bond. As with any security or capital investment, the theoretical fair value of a bond is the present value of the stream of cash flows it is expected to generate. Hence, the value of a bond is obtained by discounting the bond's expected cash flows to the present using the appropriate discount rate. Determining this rate in practice - i.e. "pricing" the bond - is done with reference to other instruments. Once the price or value has been calculated, the sensitivity of the price can then be estimated; the various yields, which relate the price of the bond to its coupons, can also be determined.