Jensen’s Measure, also known as Jensen’s Alpha, is a risk-adjusted performance metric used to evaluate the excess return generated by a portfolio or investment manager over the expected return predicted by the Capital Asset Pricing Model (CAPM). It helps determine whether the manager has added value beyond what would be expected given the level of market risk (beta) taken.
The formula is:
Jensen’s Alpha = Portfolio Return – [Risk-Free Rate + Beta × (Market Return – Risk-Free Rate)]
A positive Jensen’s Alpha indicates that the portfolio outperformed the market after adjusting for risk, while a negative alpha suggests underperformance.
This metric is particularly useful for comparing actively managed funds to passive benchmarks. For instance, if two portfolios have similar risk profiles but one shows a higher Jensen’s Alpha, it’s considered more effective at generating returns for the risk taken.
Investors often use Jensen’s Measure along with other metrics such as Sharpe Ratio and Treynor Ratio to evaluate the overall performance of an investment strategy. It is especially valuable in assessing the skill of fund managers in delivering returns beyond what can be explained by market movements alone.
