Benchmark & Alpha — Beating the Index
Definition
A benchmark is a standard reference index against which the performance of a mutual fund is measured. Alpha represents the excess return generated by a fund over and above its benchmark return, adjusted for risk. Positive alpha indicates that the fund manager has added value through security selection or market timing, while negative alpha means the fund has underperformed its benchmark on a risk-adjusted basis. SEBI mandates that every mutual fund scheme must declare a tier-1 benchmark (primary) and a tier-2 benchmark (additional) for performance comparison, and returns must be compared against the Total Return Index (TRI) version of the benchmark, which includes dividends.
In Simple Words
A benchmark serves as the reference standard — similar to comparing a student's score against the class topper. Every fund is compared to its benchmark to determine whether it is outperforming or underperforming. For example, if a large-cap fund gained 15% in a year but the Nifty 50 TRI gained 18%, that fund has actually underperformed despite showing a seemingly good absolute return, resulting in a negative alpha of -3%. This is the single most important concept for recommending actively managed funds. If a fund consistently fails to beat its benchmark, the investor is better off in a low-cost index fund. Alpha generation has become harder as Indian markets mature — the average large-cap fund alpha has been declining, and passive fund AUM has crossed ₹12 lakh crore, making it the fastest-growing segment. SEBI now mandates benchmark comparison in all performance disclosures. Jensen's Alpha adjusts for risk — it measures the excess return above what the Capital Asset Pricing Model (CAPM) would predict for a fund with that level of systematic risk (beta). A fund that takes twice the market risk and delivers twice the market return has zero alpha — it has not added any value, just more risk. True alpha comes from superior stock selection or sector allocation that generates returns beyond what the risk level would predict. In 2018, SEBI mandated that all fund performance must be compared against the TRI (Total Return Index) rather than the price return index. The TRI includes dividends reinvested, making it a higher and fairer bar for comparison. Previously, many funds appeared to generate alpha when in fact the benchmark was understated because it excluded dividends.
Real-Life Scenario
Consider the case of two large-cap funds compared over 5 years (2020-2025). Fund A delivered a CAGR of 16.5% while Fund B delivered 14.2%. The Nifty 50 TRI delivered 14.8% over the same period. Fund A has positive alpha of approximately 1.7% (before risk adjustment), meaning the fund manager added value. Fund B has negative alpha of -0.6%, meaning the investor would have been better off in an index fund with a lower expense ratio. An index fund tracking Nifty 50 with a 0.10% expense ratio would have delivered approximately 14.7% (14.8% minus expenses). Fund B at 14.2% with a 1.5% expense ratio has actually destroyed value. This illustrates why SEBI pushed for the TRI comparison — it raises the bar for active managers and supports honest fund recommendations. With Nifty 50 having delivered a long-term CAGR of approximately 12-14% over 20+ years, and the risk-free rate (10-year government bond yield) at approximately 7%, calculating Jensen's Alpha becomes instructive. If Fund A has a beta of 1.1: Jensen's Alpha = 16.5% - [7% + 1.1 x (14.8% - 7%)] = 16.5% - [7% + 8.58%] = 16.5% - 15.58% = 0.92%. The true risk-adjusted alpha is 0.92%, which is still positive — the fund manager genuinely added value even after accounting for the higher risk taken.
Key Points to Remember
Formula
Simple Alpha = Fund Return - Benchmark Return Jensen's Alpha = Fund Return - [Risk-Free Rate + Beta x (Benchmark Return - Risk-Free Rate)] This is derived from the CAPM: Expected Return = Risk-Free Rate + Beta x (Market Return - Risk-Free Rate) Jensen's Alpha measures how much the actual return exceeds the CAPM-predicted return.
Numerical Example
Given: Fund Return = 18% per annum Benchmark (Nifty 50 TRI) Return = 15% per annum Risk-Free Rate (10-year G-Sec yield) = 7% Fund Beta = 1.15 Simple Alpha = 18% - 15% = +3% Jensen's Alpha = 18% - [7% + 1.15 x (15% - 7%)] = 18% - [7% + 1.15 x 8%] = 18% - [7% + 9.2%] = 18% - 16.2% = +1.8% Interpretation: While the simple alpha is 3%, after adjusting for the fund's higher risk (beta of 1.15), the true value added by the fund manager is 1.8%. This is still positive, confirming genuine skill — not just higher risk-taking.
Frequently Asked Questions
Test Your Knowledge
3 questions to check your understanding
A mutual fund delivered a return of 20% while its benchmark TRI delivered 17%. The fund's beta is 1.2 and the risk-free rate is 7%. What is Jensen's Alpha?
Summary Notes
Benchmark is the reference index for measuring fund performance; alpha measures the excess return generated above the benchmark
Jensen's Alpha = Fund Return - [Risk-Free Rate + Beta x (Benchmark Return - Risk-Free Rate)] — it adjusts for risk taken
SEBI mandates TRI (Total Return Index) benchmarks since February 2018, tier-1 and tier-2 benchmarks for every scheme
High absolute return does not guarantee positive alpha — always check risk-adjusted performance before recommending active funds
If a fund consistently shows negative rolling alpha over 3+ years, recommend switching to a low-cost index fund tracking the same benchmark