What is alpha
Alpha is the part of an investment's return that is left over after you remove what its benchmark and its level of market risk would explain.
A benchmark is the index or portfolio you compare against, such as a stock index for an equity fund. Positive alpha means the investment did better than its risk level would predict. Negative alpha means it did worse. Alpha near zero means the return was roughly what the risk taken would explain.
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A worked example (hypothetical)
Take two funds that track the same stock index over the same period. Both beat the index by the same margin.
- Fund A has a beta equal to the index. Beta measures how strongly an investment moves with the market. Fund A took the same market risk as the index, so its whole margin over the index counts as alpha.
- Fund B has a beta well above the index. In a rising market, a high-beta fund is expected to beat the index simply because it amplifies market moves. Once you remove that expected extra return, Fund B's alpha may be small, zero or negative.
The raw returns look the same, but the risk-adjusted picture is different. That gap is what alpha measures. See Beta for how beta is estimated.
Formal definition
The standard version is Jensen's alpha, based on the Capital Asset Pricing Model (CAPM):
α = Rp − [Rf + β × (Rm − Rf)]
| Symbol | Meaning |
|---|---|
| Rp | Return of the portfolio or fund |
| Rf | Risk-free rate for the same period |
| β | Beta of the portfolio against the benchmark |
| Rm | Return of the benchmark |
In practice, alpha is usually estimated as the intercept of a regression of the portfolio's excess returns on the benchmark's excess returns. For a PKR portfolio, analysts often use a short-term government yield as Rf, or use the policy rate as a reference point. The latest policy rate decision is SBP policy rate raised by 50 bps to 12% with effect from 27.10.2026 (MPC).
Alpha is usually quoted over a stated period and often in basis points. Check whether a figure is per period or annualized before comparing funds.
Where you see the term
- Fund factsheets and annual reports. These are common for mutual funds and exchange-traded products, often next to beta, volatility and the Sharpe ratio.
- Portfolio analytics and backtest reports. Here a strategy's equity curve is compared with a benchmark. Standard trading platforms mainly show profit and drawdown, so alpha usually needs a separate calculation.
- Financial news. Phrases such as "generating alpha" or "alpha strategies" refer to returns above the market. In crypto slang, "alpha" also means information that gives an edge. That is a different, informal use of the word.
Edge cases and limits
- Benchmark choice drives the result. If you measure a small-cap fund against a large-cap index, the alpha can look large when it mostly reflects a style difference.
- Simple alpha vs Jensen's alpha. Some reports quote only the return minus the benchmark return, with no beta adjustment. That is excess return, not risk-adjusted alpha.
- Fees. Alpha before fees and alpha after fees can have opposite signs.
- Noise. Short samples produce unstable alpha estimates. A positive figure may not be statistically different from zero.
- Unstable beta. If beta changes over the period, the CAPM adjustment can be wrong.
- Past alpha is not a forecast. It describes history only. Leveraged CFD and forex trading can lose money fast, whatever a strategy's past alpha was.
Related terms
- Beta
- Annualized volatility
- Correlation coefficient
- CAGR
- Asset class
- Open-end vs closed-end fund
- Risk management
- Trading glossary
Frequent questions
What does alpha mean in simple words?
It is the return an investment earned beyond what its benchmark and its market risk would explain.
Is high alpha always good?
Not necessarily. It depends on the benchmark used, the length of the period, fees and whether the figure is statistically meaningful.
What is the difference between alpha and beta?
Beta measures how much an investment moves with the market. Alpha is the return left over after accounting for that market exposure.
Can a trader calculate alpha for a personal account?
Yes. You need your period returns, a benchmark's returns and a risk-free rate. You then apply the formula or run a regression. Platform reports alone usually do not show it.