Treynor Ratio Singapore: Measuring Returns Against Market Risk, Not Total Risk

A risk-adjusted performance metric that uses beta instead of standard deviation

The Treynor ratio measures how much excess return a portfolio or fund generates for each unit of systematic (market) risk taken, calculated as the portfolio’s return minus the risk-free rate, divided by its beta.

Not financial advice. All figures for educational reference only. Data as at October 2026.

Last updated: October 2026

Key Takeaways

• The Treynor ratio uses beta (systematic risk relative to the market) as its risk measure, unlike the Sharpe ratio, which uses total volatility (standard deviation).
• A higher Treynor ratio indicates better risk-adjusted performance relative to market risk, holding the comparison fair for funds with similar market exposure.
• The Treynor ratio is most meaningful for well-diversified portfolios, since beta only captures market risk and ignores risk specific to individual holdings.
• Singapore investors can roughly approximate a fund’s beta against the Straits Times Index when comparing local equity unit trusts or ETFs.
• The ratio was developed by Jack Treynor in the early 1960s and remains a standard metric in institutional performance evaluation, alongside the Sharpe ratio and Jensen’s alpha.

What Is the Treynor Ratio?

The Treynor ratio is one of several risk-adjusted performance measures used to judge whether an investment’s returns justify the risk taken to achieve them. Developed by American economist Jack Treynor, it divides a portfolio’s excess return (its return above the risk-free rate) by its beta, a measure of how sensitive the portfolio is to overall market movements.

The key distinguishing feature of the Treynor ratio, compared to the more commonly cited Sharpe ratio, is the risk measure used in the denominator. The Sharpe ratio uses standard deviation, capturing total volatility including risk specific to the fund’s individual holdings. The Treynor ratio uses beta, capturing only systematic risk — the portion of volatility that moves with the broader market and cannot be diversified away.

This makes the Treynor ratio particularly suited to comparing well-diversified portfolios, such as broad-based unit trusts or ETFs, where idiosyncratic, stock-specific risk has largely been diversified out, leaving market risk as the dominant remaining factor.

How Does the Treynor Ratio Work in Singapore?

For a Singapore investor comparing local equity funds, the Treynor ratio formula is: (Portfolio Return − Risk-Free Rate) ÷ Portfolio Beta. The risk-free rate benchmark commonly used in Singapore is the yield on Singapore Government Securities (SGS) or Treasury bills (T-bills) of a matching time horizon, rather than a US Treasury yield.

Beta for a Singapore equity fund is typically calculated relative to the Straits Times Index (STI) or another relevant benchmark, depending on the fund’s stated mandate. A fund investing broadly across SGX large caps would use the STI as its reference; a regional or sector-specific fund might use a more relevant regional or sector benchmark instead.

Treynor Ratio Example

Suppose a Singapore-focused equity unit trust returned 9% over a year, while the 1-year T-bill yield (used as the risk-free rate) was 3.2%, and the fund’s beta relative to the STI was 1.1. The Treynor ratio would be (9% − 3.2%) ÷ 1.1 = 5.27.

A second fund returned 8% over the same period with a lower beta of 0.8, giving a Treynor ratio of (8% − 3.2%) ÷ 0.8 = 6.0. Despite the lower headline return, the second fund produced a better return per unit of market risk taken, which the Treynor ratio captures but a simple return comparison would miss.

Advantages of the Treynor Ratio

• Isolates market risk specifically. By using beta rather than total volatility, the Treynor ratio lets investors judge performance purely against systematic risk, which is the risk that cannot be diversified away.
• Useful for comparing diversified funds. For broad unit trusts and ETFs where stock-specific risk has largely washed out, beta is often the more relevant risk measure than total standard deviation.
• Complements the Sharpe ratio. Looking at both ratios together gives a fuller picture: a fund that scores well on Sharpe but poorly on Treynor may be carrying more diversifiable (idiosyncratic) risk than its beta alone suggests.
• Simple to interpret at a glance. A higher number is better, making cross-fund comparisons within a similar asset class straightforward once the inputs are calculated.

Risks and Limitations

• Beta itself can be unstable. A fund’s beta is typically estimated from historical price data and can shift meaningfully over different time periods or market regimes.
• Not meaningful for concentrated or undiversified portfolios. For a fund with significant stock-specific risk, beta alone understates the true risk being taken, making the Treynor ratio less reliable.
• Choice of benchmark matters. Using the wrong benchmark to calculate beta (for example, a global index for a Singapore-focused fund) can distort the ratio and produce misleading comparisons.
• Negative beta or negative excess returns complicate interpretation. The ratio behaves unintuitively when beta or excess return is negative, requiring careful interpretation rather than a simple higher-is-better read.

Treynor Ratio vs Sharpe Ratio

The Bottom Line

The Treynor ratio gives Singapore investors a way to judge fund performance specifically against market risk, which is especially useful when comparing well-diversified unit trusts or ETFs where stock-specific risk is no longer the dominant factor. It works best alongside, not instead of, other risk-adjusted metrics like the Sharpe ratio.

Frequently Asked Questions

Related Terms

• Sortino Ratio Singapore
• Information Ratio Singapore
• Jensen’s Alpha Singapore
• ETF Expense Ratio Impact Calculator Singapore