CAPM is a model for pricing an individual portfolio or security. The formula for CAPM is:
(R_i )=R_f+β_i·(E (R_m )-R_f ) , where E (Ri) is the expected return of an asset, Rf is the risk-free return, E (Rm) is the expected return of the market and betai is considered the sensitivity of the expected excess asset return to the expected excess market return. Discuss how do we calculate the beta? Via regression of course.
Calculate the value of Google's beta. Use the past 36 months of returns. Try and use quantmod to download the T Bill data directly. If not, you can always download the data from another source and load it separately.