Jensenβs Alpha follows on from Alpha. It is a risk-adjsuted measure of excess return over the market portfolio. Jensenβs alpha considers excess returns to be those over and above the returns predicted by the CAPM pricing model. A positive Jensenβs alpha value means that the portfolio has beat the expected returns.
Jensenβs Alpha is calculated as follows: R(i) β (R(f) + B * (R(m) β R(f))). As such it considers the market correlation, through use of Beta, as well as the equity risk premium (R(m) β R(f)), thus providing a more robust figure than basic Alpha, which simply provides a single figure that the portfolio is above or below the market portfolio.