Treynor Ratio measures excess portfolio return per unit of systematic risk (beta), rather than total risk (standard deviation as in the Sharpe Ratio). It is the appropriate metric when a portfolio is fully diversified and only undiversifiable market risk remains.
Formula
Treynor = (Rp − Rf) / βp
Where: Rp = annualised portfolio return, Rf = risk-free rate (the conventional name for the short-term sovereign yield used as a benchmark; 91-day RBI T-bill period average), βp = portfolio beta vs declared benchmark (Nifty 50 TRI, Nifty 500 TRI, etc.).
Unlike Sharpe, Treynor ignores idiosyncratic (fund-specific) risk. A fund manager who holds 40–50 stocks is likely well-diversified; the residual risk is primarily market exposure. Treynor isolates whether that market exposure is being compensated adequately.
How it is Computed
Beta is typically measured over trailing 36 months of monthly returns against the scheme's declared benchmark (TRI-based, mandatory per SEBI Circular SEBI/HO/IMD/DF3/CIR/P/2017/126). Annualised return and Rf methodology match the Sharpe calculation. MintByte sources beta from AdvisorKhoj API; Treynor is then computed in-house as the ratio above.
Worked Example (Indian Context)
Axis Bluechip Fund – Direct Plan: 3-year annualised return = 14.9%, β vs Nifty 50 TRI = 0.78, period-average T-bill Rf = 4.4%.
Treynor = (14.9 − 4.4) / 0.78 = 10.5 / 0.78 = 13.46%
Compare Nifty 50 TRI over same period: return 13.1%, β = 1.0 by definition.
Treynor (Nifty) = (13.1 − 4.4) / 1.0 = 8.70%
The fund's Treynor of 13.46 > index Treynor of 8.70: it delivered more excess return per unit of market risk taken — even though its β (0.78) was below 1.0, meaning it was less volatile than the market.
Treynor vs. Sharpe
| Metric | Risk Denominator | Best Use Case |
|---|---|---|
| Treynor | Beta (systematic risk only) | Well-diversified funds; comparing funds within same benchmark category |
| Sharpe | Total σ (systematic + idiosyncratic) | Concentrated funds, thematic funds, partial portfolios |
| Information Ratio | Tracking error (active risk only) | Comparing two active managers vs same benchmark |
Caveats
Treynor is unreliable for concentrated or thematic funds where idiosyncratic risk dominates (a 10-stock technology sectoral fund with β = 0.9 may have substantial unsystematic risk that Treynor ignores). Beta instability — particularly for funds that shift their market-cap exposure — also makes single-period Treynor misleading. SEBI 2021/647 does not mandate Treynor disclosure; it is an analytics-layer metric.
Related terms: Beta, Sharpe Ratio, Alpha, Information Ratio, Standard Deviation.
Primary source: Treynor, J. (1965), "How to Rate Management of Investment Funds", Harvard Business Review. SEBI benchmark TRI mandate: Circular SEBI/HO/IMD/DF3/CIR/P/2017/126.
Past performance is not indicative of future returns. Mutual fund investments are subject to market risks. Read all scheme-related documents carefully. ARN-314872. APMI APRN-01658. Content is informational and not investment advice.