In this note, we present a new model that links the stock/portfolio rate of return to consumption. Our approach is more general than the existing models such as the consumption-CAPM models, that are based on very restrictive assumptions [1]. In so doing, we utilize a more advanced and appropriate theoretical and empirical framework than the ones used by previous literature. It is worth noting that previous literature mainly used simple linear regressions without a rigorous theoretical basis. We use a stochastic factor model, which includes a risky asset (portfolio, a risk-free asset and a stochastic external economic factor [2,3]. Thus, we have a twodimensional standard Brownian motion 1 2 , , s s s t s T W W on the probability space , , s P ,