Sharpe Ratio vs Sortino Ratio
Both ratios divide an excess return by a measure of risk, and both are quoted to compare strategies. The difference is the denominator. Sharpe uses total standard deviation, treating a big winning month as just as much risk as a big losing one. Sortino uses downside deviation, counting only returns below a target. For symmetric returns the two tell the same story. For skewed returns they pull apart, and the gap is itself information. This matrix sets them side by side.
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Mean excess return divided by total return standard deviation, then annualized. The universal benchmark in allocator decks and academic papers.
Pros
- Universally quoted, so it enables apples-to-apples comparison across strategies and managers
- Simple to compute and to communicate, needing only mean, standard deviation, and the risk-free rate
- Well-studied, with known standard errors and a deflated variant that corrects for selection bias
Cons
- Penalizes upside volatility identically to downside, unfairly dinging strategies with large wins
- Assumes roughly Gaussian returns and understates risk for skewed or fat-tailed distributions
- A high Sharpe can hide concentrated losses that only a downside-aware measure exposes
A common benchmark for comparison, reporting to allocators, and any strategy with roughly symmetric returns
Mean excess return divided by downside deviation, the standard deviation of returns below a target. Rewards strategies whose volatility is mostly upside.
Pros
- Penalizes only downside volatility, so it does not punish a strategy for large winning periods
- More faithful to how investors experience risk, which is losing money rather than fluctuating
- Surfaces negative skew when read against the Sharpe ratio, revealing hidden downside concentration
Cons
- Less universally quoted, so it is harder to benchmark against published Sharpe numbers
- Sensitive to the choice of target return and to having enough downside observations to estimate
- Can flatter a strategy that simply has not yet experienced its downside in the sample
Strategies with asymmetric or skewed returns, and any analysis where downside risk is the real concern
Decision Table
See the tradeoffs side by side
| Criterion | Sharpe Ratio | Sortino Ratio |
|---|---|---|
| Denominator | Total standard deviation | Downside deviation below a target |
| Penalizes upside volatility | Yes | No |
| Distribution assumption | Roughly Gaussian | Targets the downside tail directly |
| Reveals negative skew | No, can hide it | Yes, when read against Sharpe |
| Universally quoted | Yes | Less so |
| Sensitive to a target-return choice | No | Yes |
Verdict
Report both from the same return series rather than choosing one. Lead with the Sharpe ratio because it is the number every allocator recognizes, and place the Sortino ratio next to it. The relationship between the two is the signal: when Sortino sits well above Sharpe, the volatility is mostly upside and Sharpe is being unfair to the strategy; when Sortino sits below Sharpe, losses are concentrated and Sharpe is hiding downside risk. Neither number alone tells you about skew, but the pair does.
Try These Tools
Run the numbers next
Sharpe vs Sortino Calculator
Paste daily returns; get Sharpe, Sortino, Calmar, and Omega side-by-side with a recommendation on which ratio fits your distribution.
Risk-Adjusted Returns Calculator
Paste a returns CSV. Sharpe, Sortino, Calmar, Omega, alpha, beta, tracking error, information ratio, max drawdown, and tail moments — plus.
Returns Distribution Analyzer
Paste a returns CSV. Histogram, normal-overlay, QQ plot, skewness, excess kurtosis, Jarque-Bera test, tail-weight index. See why Sharpe alone misleads.
FAQ
Questions people ask next
The short answers readers usually want after the first pass.
Sources & References
- The Sharpe Ratio — William F. Sharpe, Journal of Portfolio Management (1994)
- Downside Risk — Frank A. Sortino and Robert van der Meer, Journal of Portfolio Management (1991)
Related Content
Keep the topic connected
Sharpe Ratio
Sharpe ratio defined, when it lies (skew, fat tails, autocorrelation), and how to read a Sharpe number you didn't compute yourself.
Sortino Ratio
Sortino ratio: same numerator as Sharpe, denominator only counts downside volatility. When it's the right number to look at.
Sharpe vs Sortino
Sharpe vs Sortino: when the gap between the two tells you something real about a strategy's tail behaviour — and when it's just noise from a small sample.
Sharpe vs Sortino Worked Examples
Worked examples showing when Sharpe and Sortino diverge: same mean return, different volatility shapes. Every number computed from the standard annualized formulas.