Bond yield can be described by a single factor model. The single factor model holds that the bond yield is affected by the overall market risk factors, that is, the market risk premium. This model is called single factor or market model.

CAPM is a capital asset pricing model, so it is usually used to calculate the expected rate of return of stocks. Although bonds can be regarded as the deformation of equity capital, the characteristics of bonds are different from those of stocks, so they are not suitable for the calculation of expected returns of bonds. Therefore, the yield of bonds is usually described by a single factor model.