This model relies on only one explanatory factor for a securitys $($or portfolios$)$ required return and imposes a large number of restrictive and unrealistic assumptions.Capital Asset Pricing ModelFama$-$French three$-$factor modelThis model argues that a securitys required return is a function of the market risk premium, the companys size, and the companys book$-$to$-$market value ratio.Fama$-$French three$-$factor modelCapital Asset Pricing Model