The Sharpe ratio is the annualised excess return of a strategy divided by its annualised volatility. A Sharpe of 1.0 is solid, 2.0 is institutional-grade, and above 3.0 is rare and often suggests either short backtest length or hidden leverage. The metric measures reward per unit of risk, not absolute return.
Defined by William Sharpe 1966 as (R_p − R_f) / σ_p, where R_p is portfolio return, R_f is the risk-free rate, and σ_p is the standard deviation of excess returns. The intuition: a 30% return with 60% volatility (Sharpe 0.5) is worse than a 10% return with 5% volatility (Sharpe 2.0) because the second strategy compounds more reliably. APEX targets Sharpe in the 1.0-1.5 range across realised forward returns post-2026-05-16.