Compute the Sortino ratio from portfolio return, risk-free rate and downside deviation — a downside-risk-only alternative to the Sharpe ratio.
仅用下行波动衡量风险调整收益。
| Item | Formula / Note | Source / Standard |
|---|---|---|
| Sortino ratio | Sortino = (R_p - R_f)/σ_d (downside) | Sortino & Price (1994) |
| vs Sharpe | Uses downside deviation only | Downside risk only |
| Parameters | R_p portfolio, R_f risk-free, σ_d downside | Standard definition |