VaR, Expected Shortfall, and maximum drawdown compared
| Metric | Question Answered | Limitation |
|---|---|---|
| VaR (95%) | What’s the worst loss 95% of the time? | Says nothing about the other 5% |
| Expected Shortfall (95%) | When losses exceed VaR, what’s the average? | Harder to backtest |
| Maximum Drawdown | What’s the worst peak-to-trough decline? | Only uses one data point (the worst) |
Why Expected Shortfall always exceeds VaR
Expected Shortfall is always larger than VaR and gives a more honest picture of tail risk. If your 95% VaR is $50K but your Expected Shortfall is $150K, the tail is very fat — your rare bad days are three times worse than the VaR threshold suggests.
Compare VaR and Expected Shortfall on your portfolio
Compare VaR to Expected Shortfall for your portfolio. If ES is much larger than VaR, your portfolio has significant tail risk — the rare bad events are much worse than the typical bad event.
Same VaR, very different tail risk
Portfolio A: VaR $50K, ES $60K. Portfolio B: VaR $50K, ES $200K. Same VaR, very different risk profiles. Which is riskier?
Why tail risk is where portfolios blow up
Reading tail risk from Expected Shortfall
Portfolio A: 95% VaR $100K, 99% VaR $200K, Expected Shortfall (95%) $250K. Portfolio B: 95% VaR $100K, 99% VaR $150K, ES $140K. Which has worse tail risk?
Check your understanding
Sit with the ideas.
Two portfolios both report a 95% daily VaR of $50,000. Portfolio X holds diversified large-cap stocks. Portfolio Y holds concentrated biotech positions. Which likely has higher Expected Shortfall, and why?
Why: