Alpha

Alpha is the excess return of a portfolio or fund above what would be predicted by its market exposure (beta). It measures the value added — or destroyed — by active management decisions, after accounting for the risk taken relative to the market.

Jensen's Alpha Formula

α = R_p − [R_f + β × (R_m − R_f)]

Where: R_p = portfolio return, R_f = risk-free rate (typically India 91-day T-Bill rate, published by RBI at rbi.org.in), β = portfolio beta vs benchmark, R_m = market (benchmark) return.

Positive alpha = outperformance adjusted for risk. Negative alpha = underperformance. An alpha of +3% means the fund delivered 3 percentage points more than a passive benchmark-tracking portfolio with the same level of market risk.

Worked Example (Indian Context)

A diversified equity fund delivers 18% return over a calendar year. Nifty 50 TRI returns 14%. The fund's beta (measured against Nifty 50 TRI) is 0.92. India 91-day T-Bill rate: 7%.

Alpha = 18 − [7 + 0.92 × (14 − 7)] = 18 − [7 + 6.44] = 18 − 13.44 = +4.56%

The fund outperformed its risk-adjusted expected return by 4.56 percentage points in that year.

Alpha in SEBI-Regulated Fund Evaluation

SEBI does not mandate alpha disclosure in mutual fund factsheets; the required metrics are NAV, expense ratio, trailing CAGR, and risk ratios (standard deviation, Sharpe ratio) per SEBI Circular SEBI/HO/IMD/DF2/CIR/P/2021/647. However, AMFI and independent analytics providers (Value Research, Morningstar India) calculate and publish alpha as part of risk-adjusted return analysis.

Under SEBI (Mutual Funds) Regulations 1996, Schedule VII and SEBI LODR Regulation 46, fund performance benchmarking against TRI (Total Return Index) became mandatory from 1 February 2018 per SEBI Circular SEBI/HO/IMD/DF3/CIR/P/2017/126. TRI-based benchmarking gives a more meaningful alpha denominator than price-index benchmarking (TRI includes dividend reinvestment, approximating the fund's total return more accurately).

Source: SEBI Circular SEBI/HO/IMD/DF3/CIR/P/2017/126 (TRI benchmarking mandate); SEBI MF Regulations 1996, Schedule VII.

Interpreting Alpha: Cautions

Consideration	Detail
Time horizon	Alpha over 1 year is largely noise. Consistent alpha over 5–7 years across multiple market cycles is more meaningful.
Benchmark sensitivity	Using the wrong benchmark artificially inflates or deflates alpha. A midcap fund benchmarked against Nifty 50 will show spurious alpha in a midcap bull run.
Luck vs. skill	Academic literature (Carhart 1997, SEBI-AMFI study 2022) documents that majority of active manager outperformance does not persist. Statistically significant alpha requires >10 years of data.
Style drift	A fund's beta (and thus alpha calculation basis) can change if the manager drifts from large-cap to mid-cap allocation. Rolling alpha computed with a rolling beta is more accurate.

Alpha vs. Information Ratio vs. Sharpe Ratio

Metric	What It Measures	When to Use
Alpha	Excess return above CAPM-predicted return	Evaluating active manager skill vs benchmark
Information Ratio	Active return ÷ tracking error (consistency of active bets)	Comparing two active managers
Sharpe Ratio	Excess return above risk-free rate ÷ total standard deviation	Absolute risk-adjusted return (independent of benchmark)

Practical Use for Investors

When evaluating an actively managed equity fund (category: large cap, flexicap, mid cap) per SEBI's Categorization Circular SEBI/HO/IMD/DF3/CIR/P/2017/114, compute 3-yr and 5-yr rolling alpha against the scheme's declared benchmark TRI. If rolling alpha is consistently negative (>60% of rolling windows), the fund has not added value relative to a passive alternative tracking the same index — and the active management expense ratio premium is not justified.

Source: SEBI Categorization Circular SEBI/HO/IMD/DF3/CIR/P/2017/114; RBI 91-day T-Bill rates (rbi.org.in/Scripts/BS_PressReleaseDisplay.aspx).

Related terms: Beta, Sharpe Ratio, Rolling Returns, XIRR.

Past performance is not indicative of future returns. ARN-314872. APMI APRN-01658. Content is informational.