what is the difference between the treynor and sharpe ratio

Both put excess return over a measure of risk, but they use different denominators. The Sharpe ratio divides by total volatility (standard deviation), capturing all the risk a portfolio experiences; the Treynor ratio divides by beta, capturing only systematic, market-driven risk. For a well-diversified portfolio, where company-specific risk has largely been washed out, the two rank portfolios similarly. For an undiversified portfolio carrying a lot of stock-specific risk, Treynor can look flattering because beta ignores that idiosyncratic risk — which is exactly why the choice of ratio matters.

when should you use the treynor ratio

The Treynor ratio is most appropriate when the portfolio being judged is one piece of a larger, well-diversified whole, so that only its market risk — its beta — is what it adds to the overall picture. That makes it a natural fit for comparing well-diversified funds or sleeves within a bigger portfolio. It is less suitable for a concentrated, undiversified portfolio, because beta ignores the company-specific risk such a portfolio carries, and Treynor would give it undeserved credit. In that case the Sharpe ratio, which counts total risk, is the fairer measure.

What is the Treynor ratio and how it differs from Sharpe

The Sharpe ratio divides excess return by total volatility. The Treynor ratio makes one change with a big consequence: it divides by beta instead — return per unit of market risk. That swap sounds academic, but it changes which portfolios look good and why, and knowing when each applies is a mark of a serious analyst.

Excess return over beta

Treynor takes the same numerator as Sharpe — the return above the risk-free rate — but its denominator is beta, the portfolio’s sensitivity to the market. It asks: for every unit of non-diversifiable, market-driven risk you took, how much did you earn? Because it ignores company-specific risk entirely, it implicitly assumes that risk has been diversified away and only market exposure is left to be compensated.

Worked example

Two funds, same excess return

Excess return 9% each

Fund A excess returnBeta 0.89%

Fund A TreynorMore return per unit of market risk9 ÷ 0.8 = 11.25

Fund B excess returnBeta 1.59%

Fund B TreynorLess return per unit of market risk9 ÷ 1.5 = 6.0

Same returnA took less to earn itDifferent market risk

Both funds delivered a 9% excess return, but Fund A did it with far less market exposure (beta 0.8 versus 1.5), so its Treynor ratio is nearly double. If these are sleeves inside a diversified portfolio, A added the same return for much less of the market risk that actually matters to the whole — which is precisely what Treynor is built to reward.

Check yourself

You are ranking two well-diversified equity funds. One has a beta of 0.9, the other 1.4, and both earned the same excess return. Which has the better Treynor ratio, and what does it mean?

Simple bhasha mein

Market-risk ke hisaab se return

Sharpe total volatility se baanta hai; Treynor sirf beta (market risk) se — matlab return per unit market-exposure. Dono fund ne 9% extra kamaya, par ek ne beta 0.8 pe (Treynor 11.25), doosre ne 1.5 pe (6.0) — pehla behtar. Diversified portfolio ke tukde ko jaanchne ke liye Treynor sahi; akela, concentrated portfolio ho toh Sharpe — kyunki beta company-specific risk ignore kar deta hai.

What to remember

The Treynor ratio is excess return divided by beta — return per unit of market risk.
It differs from Sharpe, which divides by total volatility instead of beta.
The two agree for well-diversified portfolios and diverge for concentrated ones.
Use Treynor for a piece of a diversified whole; use Sharpe for a standalone portfolio.
It relies on beta, which is estimated and drifts, so a stale beta undermines it.

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Common questions

Short, direct answers to what people ask about this topic.

what is the treynor ratio: The Treynor ratio measures how much excess return a portfolio earned for each unit of market risk it took, where market risk is measured by beta. It is calculated as the return above the risk-free rate divided by the portfolio’s beta, so a higher number means more reward per unit of the risk that cannot be diversified away. It is closely related to the Sharpe ratio but answers a subtly different question: not "how much return per unit of total volatility" but "how much return per unit of exposure to the market itself".
what is the difference between the treynor and sharpe ratio: Both put excess return over a measure of risk, but they use different denominators. The Sharpe ratio divides by total volatility (standard deviation), capturing all the risk a portfolio experiences; the Treynor ratio divides by beta, capturing only systematic, market-driven risk. For a well-diversified portfolio, where company-specific risk has largely been washed out, the two rank portfolios similarly. For an undiversified portfolio carrying a lot of stock-specific risk, Treynor can look flattering because beta ignores that idiosyncratic risk — which is exactly why the choice of ratio matters.
when should you use the treynor ratio: The Treynor ratio is most appropriate when the portfolio being judged is one piece of a larger, well-diversified whole, so that only its market risk — its beta — is what it adds to the overall picture. That makes it a natural fit for comparing well-diversified funds or sleeves within a bigger portfolio. It is less suitable for a concentrated, undiversified portfolio, because beta ignores the company-specific risk such a portfolio carries, and Treynor would give it undeserved credit. In that case the Sharpe ratio, which counts total risk, is the fairer measure.

The Treynor ratio: return per unit of market risk

Excess return over beta

Common questions