Sharpe Ratio
Return per unit of total risk — how much reward you earn for each unit of volatility taken. Higher is better.
Sharpe Ratio = (Strategy Return − Risk-Free Rate) / Std Dev of Returns
The Sharpe Ratio measures risk-adjusted performance by dividing excess return (return above the risk-free rate) by the standard deviation of returns. It is the most widely cited single performance metric for trading strategies and funds.
A Sharpe above 1.0 is generally considered acceptable; above 2.0 is strong; above 3.0 is exceptional. However, Sharpe penalises upside volatility as much as downside — enter the Sortino Ratio for a more nuanced view.
On the desk
Strategy returns 18% annually, risk-free rate 4%, standard deviation 10%. Sharpe = (18% − 4%) / 10% = 1.4. Solid risk-adjusted performance.