What is R-Squared?
R-Squared (R²) tells you what percentage of a fund's return movements are explained by movements in the benchmark index. An R² of 90 means 90% of the fund's ups and downs are simply the benchmark going up and down — the manager is only responsible for the remaining 10%.
R-Squared ranges from 0 to 100. A pure index fund would have R² of 100. A fund with R² of 55 is moving very independently of the benchmark — either taking very different sector bets or picking stocks that are barely correlated to the index.
The Closet Indexer Problem
The most important practical use of R-Squared is catching closet indexers — funds that charge active management fees (1–2% expense ratio) but are essentially running a near-index portfolio. If a fund has R² of 95+, you are paying full active fees for index-like performance. You would be better served by a low-cost index fund.
When R-Squared Reveals Benchmark Hugging
In the 2021–2022 small cap rally, several fund houses launched new small cap schemes that closely mirrored the Nifty Smallcap 250 composition. These funds had R² above 90 but charged 1.5–1.8% expense ratios. Investors who compared these against a Nifty Smallcap 250 index fund (expense ratio ~0.3%) were effectively paying 1.2–1.5% extra per year for no active value. Over 15 years, that difference compounds to lakhs on a modest investment.
| Fund | R² vs Smallcap 250 | Active Share Implication | Verdict |
|---|---|---|---|
| Nippon India Small Cap | 82 | Meaningful active bets | Genuinely Active |
| SBI Small Cap | 79 | Significant independent positions | Genuinely Active |
| Hypothetical Closet Indexer | 94 | Barely different from index | Closet Indexer |
R-Squared and the Validity of Beta
There is a crucial technical point: Beta is only meaningful when R-Squared is high. If a fund's R² vs Nifty 50 is 45, the Beta vs Nifty 50 is almost meaningless — the fund is not tracking Nifty 50 closely enough for Beta to be statistically valid. Always check R² before interpreting Beta.