OmegaRatio Node
Probability-weighted gains vs losses metric
Overview
Omega Ratio measures expected gains above a threshold divided by expected losses below that threshold, both probability-weighted. It's superior to Sharpe Ratio because it accounts for actual return distribution shape (skewness, kurtosis) rather than assuming normality. Omega > 2.0 is excellent; Omega > 1.0 is good.
Unlike Sharpe which penalizes all volatility equally, Omega only penalizes downside volatility. This better captures what traders care about: making more on winners than losing on losers. A strategy with Omega = 3.0 wins 3x more on gains than it loses on declines above/below threshold.
Formula & Calculation
Threshold: Usually 0% (risk-free rate or MAR)
Gains area above threshold / Losses area below threshold
Denominator: Expected downside below threshold
Parameters
| Parameter | Default | Description |
|---|---|---|
| period | 252 | Trading days for calculation |
| threshold | 0.0% | Minimum acceptable return (MAR) |
Common Use Cases
1. Strategy Comparison
Compare strategies on Omega basis: Strategy A (Omega=2.5) beats Strategy B (Omega=1.2) despite similar Sharpe. Omega captures real preferences.
2. Portfolio Optimization
Maximize portfolio Omega instead of Sharpe. Weights toward strategies with high upside probability and low downside exposure.
3. Risk Threshold Setting
Omega shows margin-of-safety: If threshold = 0%, Omega = 2 means 2x more gains than losses. Set stops and targets to match threshold.
4. Distribution Analysis
Omega > Sharpe suggests positive skew (good). Omega < Sharpe suggests negative skew (risky). Different thresholds reveal distribution shape.
Advantages & Limitations
Advantages
- No normality assumption
- Only penalizes downside
- Threshold-flexible (set own MAR)
- Captures distribution shape
Limitations
- Threshold selection critical
- Requires sufficient samples
- Unstable for low-probability outcomes
- Hard to benchmark (vs Sharpe)