Learn

Sortino vs Sharpe Ratio

Sortino and Sharpe ratios both measure risk-adjusted return as (excess return / risk). They differ in how risk is measured: Sharpe uses standard deviation of all returns; Sortino uses standard deviation of only the losing periods. The choice matters when your strategy has asymmetric upside.

By Keel Research Team · Updated May 13, 2026

Both ratios answer the same question: "How much return did I get per unit of risk I took?" The numerator is the same — excess return over the risk-free rate. The difference is entirely in the denominator: how we define "risk."

Sharpe defines risk as standard deviation of all returns — upside spikes and downside losses are treated symmetrically. Sortino defines risk as standard deviation of only the losing periods (or returns below a configurable threshold). For strategies where the upside and downside are roughly mirror images, both ratios give similar answers. For asymmetric strategies, they diverge meaningfully.

The formulas, side-by-side

Both ratios share the same structure:

ratio = (mean_return − risk_free_rate) / risk_denominator

Sharpe uses standard deviation of all returns:

sharpe_risk = stddev(returns)

Sortino uses downside deviation — the standard deviation calculated using only returns below a "minimum acceptable return" (MAR), which is conventionally zero:

sortino_risk = sqrt(mean of (r − MAR)² where r < MAR)

Annualization for both is the same: multiply by sqrt(periods_per_year). Daily returns scale by sqrt(252), monthly by sqrt(12), and so on.

When each is the right lens

The choice between ratios depends on what kind of risk you care about and what shape your strategy's returns are.

Use Sharpe when:

  • Returns are roughly symmetric (carry, market-making, mean-reversion at scale).
  • You want to compare against benchmarks — most fund-industry conventions use Sharpe.
  • You care about all volatility, including upside surprises (which can indicate model misspecification).

Use Sortino when:

  • Returns have positive skew — fat upside tails, smaller downside (trend, breakout, momentum, long-options).
  • You explicitly only care about downside risk, not "good volatility."
  • Your strategy backtest shows Sharpe under 1 but you suspect upside vol is being unfairly punished.

For Hyperliquid carry strategies — the funding-carry pattern with mostly stable hourly P&L — Sharpe and Sortino tend to be similar. For trend-following on volatile altcoins, Sortino is consistently higher and more honestly represents the trade's risk character.

What the ratio between them tells you

Compute Sortino / Sharpe. Three regimes:

  • Near 1.0: upside and downside vol are roughly equal. Symmetric strategy. Use Sharpe.
  • 1.3 to 1.8: meaningful asymmetry. Strategy has positive skew — winning trades meaningfully bigger than losing trades. Sortino is the better metric to report.
  • Above 2.0: rare. Either real fat-tailed positive skew (good — investigate) or sample-size artifact (the few big wins drive the ratio, robustness is unclear).

The Sortino/Sharpe ratio is itself a strategy-character signal. Highly skewed strategies are typically more psychologically difficult to hold through losing streaks (you stop, then miss the next big winner), so a high Sortino/Sharpe sometimes reflects strategies that look great in backtest but are hard to actually run live.

Both at once with real numbers

The Sortino vs Sharpe calculator computes both ratios from a returns series with proper annualization and a configurable risk-free rate. It also surfaces the Sortino/Sharpe ratio so you can read strategy asymmetry directly.

For a real Keel strategy example, the funding carry strategy reports Sharpe 2.17 on a 20-month backtest — that's institutional-grade. Sortino would typically be similar on a carry trade (symmetric P&L), confirming Sharpe is the right metric to lead with for that strategy.

This article is educational. Risk-adjusted return ratios are point estimates from finite samples; small samples produce unreliable ratios. Always cross-check against max drawdown and direct equity-curve inspection.
Automate it

Trade systematically on Keel

Keel is a Strategy OS for AI-assisted systematic trading on Hyperliquid. Backtest, optimize, and run live strategies across single-stock perps, indices, and crypto majors — realistic fees, slippage, and funding modeled.

Free to start — connect a Hyperliquid wallet when you’re ready to go live.

What you can do
  • Backtest any strategy with realistic fees, slippage, and funding.
  • Optimize parameter grids by Sharpe, drawdown, hit rate.
  • Deploy live to HL with stops + position limits + funding-aware execution.
  • Iterate with AI — describe a thesis, get a tradeable pipeline.
FAQ

Sortino vs Sharpe — questions

What's the one-sentence difference between Sortino and Sharpe?

Sharpe divides excess return by all volatility (upside + downside); Sortino divides by downside volatility only. Sortino is more forgiving for strategies that have big winners and small losers.

Which should I prefer for strategy evaluation?

For strategies with symmetric P&L (carry, market-making, mean-reversion at scale), Sharpe and Sortino are similar — pick Sharpe for convention. For strategies with positive skew (trend-following, breakout, options) where big winners drive returns, Sortino is more honest about real risk. For directional or asymmetric crypto strategies, Sortino is often the better lens.

What's a good Sortino or Sharpe ratio?

Rough trading-strategy benchmarks. Under 1: not worth the operational complexity over buy-and-hold. 1-2: real edge, but path-dependent. 2-3: institutional-grade — most pro traders aim here. Over 3: usually too good to be true on a long sample. Check for survivorship bias, look-ahead bias, or in-sample overfitting before committing capital.

How is the annualization done?

Multiply the per-period ratio by sqrt(N) where N is periods-per-year. Daily returns → sqrt(252). Weekly → sqrt(52). Monthly → sqrt(12). This standard scaling assumes returns are roughly independent across periods. For highly autocorrelated returns (e.g. monthly hedge-fund-of-funds), sqrt-scaling overstates the annualized ratio.

My Sortino is much bigger than my Sharpe — what does that mean?

It means upside volatility dominates downside volatility — your strategy has positive skew. The ratio between Sortino and Sharpe is a useful signal: greater than 1.3 indicates meaningful asymmetry; greater than 2.0 is rare and worth investigating (could be real edge from a trend-friendly regime, could be sample-size artifact).

What's a "minimum acceptable return" (MAR) in the Sortino formula?

Sortino's downside-deviation calculation only includes returns below a threshold (usually 0 — i.e. only periods where you lost money). The MAR is configurable. For most use cases, set MAR = 0 (treat any loss as downside). Setting MAR = risk-free rate makes Sortino more comparable to Sharpe under risk-adjusted-excess-return framing.