What Is Sharpe Ratio in Trading?
The Sharpe ratio measures the return a trading strategy earns per unit of total risk (volatility) it takes on, calculated by dividing excess return over a risk-free rate by the standard deviation of returns. It rewards smooth, consistent gains over lumpy, volatile ones, even when both produce similar total profit.
Formula
Sharpe Ratio = (Average Return − Risk-Free Rate) ÷ Standard Deviation of ReturnsWorked example
A trader’s strategy averages a 3% return per month, against a risk-free rate proxy (like a short-term Indian T-bill) of roughly 0.5% per month. The standard deviation of their monthly returns over the past year is 2%.
Monthly Sharpe ratio = (3% − 0.5%) ÷ 2% = 1.25. This tells the trader they are earning 1.25 units of return for every unit of volatility endured — a solid, if not exceptional, risk-adjusted result for an active strategy.
What's a good number?
For an active trading strategy, a Sharpe ratio above 1 is generally considered good, above 2 is very good, and above 3 is excellent and comparatively rare over a meaningful sample of trades or months.
A Sharpe ratio below 0.5 suggests the returns are not adequately compensating for the volatility being taken on. Treat any Sharpe calculated over just a few months of live trading with caution — it takes a reasonably large sample of returns before the number becomes statistically trustworthy.
Common mistakes traders make with sharpe ratio
- Calculating Sharpe ratio over too few trades or months, producing a number that looks impressive but is really just a lucky short stretch.
- Ignoring the risk-free rate entirely, or using an outdated one, which skews the "excess return" half of the formula.
- Comparing Sharpe ratios calculated on different timeframes (daily versus monthly) without annualizing them consistently, making the comparison meaningless.
- Treating Sharpe as the only risk-adjusted metric that matters and ignoring drawdown — Sortino and Calmar exist specifically to cover what Sharpe misses.
TradeMind computes Sharpe ratio automatically from your trade history, alongside Sortino ratio and SQN, so you get a full picture of risk-adjusted performance without a spreadsheet in your analytics dashboard.