If you have the historical returns on stock A, the returns on the Market Index and on the risk-free asset you can calculate the Beta of stock A. Assume that COV(A ,Market)=773.31 and the Standard deviation of the market (M) return is 21.86% then A's Beta is equal to: 1.6183 1.299 1.3584 1.50 1.456 1.1560