The return a fund earned above or below what its benchmark or level of market risk would explain — a rough gauge of a manager’s value-add.
Alpha measures how much a fund’s return differed from what you would have expected given its benchmark or market exposure. Positive alpha means the fund did better than that expectation; negative alpha means it did worse. In its simplest form, alpha is the fund’s return minus its benchmark’s return. The more formal version (Jensen’s alpha) adjusts for beta — how sensitive the fund is to market moves.
Why it matters
Active funds cost more than index funds because they aim to beat the market. Alpha is one way to check whether that happened, after costs, over a given period.
How to read it
- Check the period. Alpha over one year says little; alpha that persists across market cycles says more.
- Check the benchmark. Alpha is only as meaningful as the benchmark it is measured against. A mid-cap fund compared with a large-cap index can show “alpha” that is really a different kind of risk.
- It is already net of costs. Factsheet returns are after the expense ratio, so the alpha you see is after fees.
Common misconceptions
- “Positive alpha proves skill.” It may reflect skill, luck, or exposure to risks the benchmark does not capture. Telling them apart takes a long record.
- “High past alpha predicts future alpha.” Evidence on fund performance suggests outperformance is hard to sustain consistently. Treat alpha as context, not a forecast.
In India: Equity scheme factsheets often report alpha, beta, standard deviation and Sharpe ratio. Methods and periods differ between fund houses, so compare like with like.
Formula
Simple alpha = Fund return − Benchmark return. Jensen’s alpha = Fund return − [Baseline return + Beta × (Benchmark return − Baseline return)], where the baseline is usually a short-term government security yield.
Worked example
For illustration, assume that over three years a fund returned 14% a year, its benchmark 12%, its beta is 1.1 and the short-term government security yield is 6%. Simple alpha = 2 percentage points. Jensen’s alpha = 14 − [6 + 1.1 × (12 − 6)] = 14 − 12.6 = 1.4 percentage points.
Figures are for illustration only — not a forecast or a recommendation.
Related terms
Beta
How much a fund or stock has tended to move relative to its benchmark; a beta of 1.2 suggests swings about 20% larger in either direction.
Benchmark
The index a fund’s performance is measured against, chosen to represent the market or segment the fund invests in.
Sharpe ratio
The return earned above a baseline, such as a Treasury bill yield, for each unit of volatility taken; higher means more return per unit of risk.
Standard deviation
A measure of how widely an investment’s returns have varied around their average; a higher figure means a bumpier ride.
Index fund
A mutual fund that aims to replicate a market index by holding the index’s constituents in the same proportions, at low cost.