Max Drawdown
The largest peak-to-trough portfolio decline — a key risk measure.
Max drawdown (MDD) is the largest percentage decline from a peak to a subsequent trough in a portfolio's value before a new peak is reached. It measures the worst-case loss an investor would have experienced by entering at the highest point and exiting at the lowest point during any period. Max drawdown is one of the most important risk metrics because it captures the real pain of a strategy's worst period.
Why It Matters
Returns only tell half the story. A strategy that returns 25% annually sounds excellent — until you learn it suffered a 60% drawdown along the way. Most traders cannot psychologically or financially survive a 60% drawdown, even if the strategy eventually recovers. Max drawdown tells you the price of admission for any strategy's returns.
For options traders, max drawdown is particularly relevant because many premium-selling strategies produce smooth returns for months and then experience a sharp, sudden drawdown during a market event. Understanding and planning for your strategy's expected max drawdown is the difference between staying in the game and being forced to quit at the worst possible time.
How It Works
Calculating max drawdown:
- Track the running peak of your portfolio value over time
- At each point, calculate the drawdown: (Peak - Current Value) / Peak
- The max drawdown is the largest drawdown observed
Max Drawdown = (Peak Value - Trough Value) / Peak Value
What max drawdown tells you:
- The worst historical loss you would have experienced
- How much capital you need to withstand the worst period
- Whether the strategy's returns justify the worst-case risk
Recovery from drawdowns: Drawdowns are asymmetric — a 50% loss requires a 100% gain to recover. This compounding penalty makes large drawdowns especially damaging:
| Drawdown | Gain Needed to Recover |
|---|---|
| 10% | 11% |
| 25% | 33% |
| 50% | 100% |
| 75% | 300% |
Max drawdown for common strategies:
- S&P 500 buy-and-hold: approximately 55% (2007-2009)
- Diversified short premium options: typically 15-30% during market stress
- Naked short puts: can exceed 50% during crashes
- Long volatility / tail hedging: can exceed 40% during calm periods (death by a thousand cuts)
Using max drawdown for position sizing: Multiply your strategy's historical max drawdown by 1.5 to 2x to estimate future worst case (the worst drawdown is always ahead of you). Ensure your position size keeps this estimated worst case within a level you can survive both financially and emotionally.
Max drawdown and time to recovery: Equally important is how long recovery takes. A 30% drawdown that recovers in 3 months is very different from a 30% drawdown that takes 3 years. Track both the depth and duration of drawdowns.
Quick Example
Your options portfolio starts at $100,000 and grows to $125,000 over 6 months. Then a market selloff causes the portfolio to drop to $90,000. It eventually recovers to $130,000.
Max drawdown = ($125,000 - $90,000) / $125,000 = 28%
To recover from $90,000 to the previous peak of $125,000, you needed a 38.9% return — significantly more than the 28% you lost. If your annualized return is 20%, this recovery takes roughly 1.5-2 years.
If you sized positions using quarter Kelly and your max drawdown is 28%, you might consider reducing size so that the worst case stays below 20% — a level most traders can tolerate without abandoning their strategy.