Alpha
Measure of
risk-adjusted performance. Some refer to the alpha as the difference between the investment return and the benchmark return. However, this does not properly adjust for risk. More appropriately, an alpha is generated by regressing the
security or
mutual fund's excess return on the benchmark (for example
S&P 500) excess return. The
beta adjusts for the
risk (the slope coefficient). The alpha is the intercept. Example: Suppose the mutual fund has a return of 25%, and the
short-term interest rate is 5% (excess return is 20%). During the same time the
market excess return is 9%. Suppose the beta of the mutual fund is 2.0 (twice as risky as the S&P 500). The
expected excess return given the risk is 2 x 9%=18%. The actual excess return is 20%. Hence, the alpha is 2% or 200
basis points. Alpha is also known as the
Jensen Index. The alpha depends on the benchmark used. For example, it may be the intercept in a multifactor model that includes risk factors in addition to the S&P 500. Related:
Risk-adjusted return.
Alpha.
Alpha measures risk-adjusted return, or the actual return an equity security provides in relation to the return you would expect based on its beta. Beta measures the security's volatility in relation to its benchmark index.
If a security's actual return is higher than its beta, the security has a positive alpha, and if the return is lower it has a negative alpha.
For example, if a stock's beta is 1.5, and its benchmark gained 2%, it would be expected to gain 3% (2% x 1.5 = 0.03, or 3%). If the stock gained 4%, it would have a positive alpha.
Alpha also refers to an analyst's estimate of a stock's potential to gain value based on the rate at which the company's earnings are growing and other fundamental indicators.
For example, if a stock is assigned an alpha of 1.15, the analyst expects a 15% price increase in a year when stock prices are generally flat. One investment strategy is to look for securities with positive alphas, which indicates they may be undervalued.