The market risk premium is the slope of the security market line. Slope is the rise over the run, which in this case is the difference between the market return and the risk-free rate divided by a beta of 1.0 minus a beta of zero. If a stock is correctly priced the reward-to-risk ratio will be constant and equal to the slope of the security market line. Thus, every stock that is correctly priced will lie on the security market line.