Drawdown
The peak-to-trough decline in a trading account's value, expressed as a percentage from the highest point to the lowest point before a new high is reached.
What Drawdown Means
Drawdown is the peak-to-trough decline in a trading account's value, expressed as a percentage from the highest equity point to the lowest point before recovery. It is the most practical measure of trading risk because it reflects what a trader actually experiences: watching their account shrink. Research by Magdon-Ismail & Atiya (*The Annals of Applied Probability*, 2004) demonstrated that the expected maximum drawdown of a random walk grows with the square root of the number of trades — meaning drawdowns deepen predictably as trading horizons extend.
Types of Drawdown
Maximum Drawdown (MDD): The largest peak-to-trough decline in account history. This is the number that tests your psychological limits.
Average Drawdown: The mean of all drawdowns over a period. Gives a sense of typical pain.
Drawdown Duration: How long it takes to recover from a drawdown back to the previous peak. According to AQR Capital Management research (2019), the median recovery time from a 30% drawdown in equity strategies is approximately 14 months.
The Recovery Math
Drawdowns are mathematically asymmetric. The recovery required is always larger than the loss:
| Drawdown | Recovery Needed |
|----------|----------------|
| 10% | 11.1% |
| 20% | 25.0% |
| 30% | 42.9% |
| 50% | 100.0% |
| 75% | 300.0% |
This asymmetry is why preventing large drawdowns matters more than maximizing gains.
Psychological Ruin Thresholds
A CFA Institute survey (2020) found that 62% of professional fund managers identified drawdown tolerance as the primary determinant of strategy longevity. Most traders have a psychological breaking point well below 100% loss:
- 20% drawdown: doubt and second-guessing begin
- 30% drawdown: strategy changes, rule-breaking
- 40% drawdown: most traders quit or revenge trade
Your real "ruin" is hitting the point where you can no longer trade your system as designed.
Managing Drawdown Risk
1. Size positions so that maximum expected drawdown stays within your tolerance
2. Use Monte Carlo simulation to see the drawdown distribution, not just the average
3. Define your personal max drawdown before you start trading
4. Reduce position size if drawdown approaches your threshold
The Risk of Ruin Calculator estimates drawdown probability. RangeSight generates full drawdown curves across 10,000 simulated paths.
Key Takeaway
The peak-to-trough decline in a trading account's value, expressed as a percentage from the highest point to the lowest point before a new high is reached. Use RangeSight Studio's Monte Carlo simulator to model drawdown with 10,000 simulated paths and real market volatility.
This explains the concept.
But how drawdown affects your specific strategy depends on your parameters, position sizing, and market conditions.
Test your strategy to see how consistent it actually is → Run survival test
See the full distribution with real market data
10,000 Monte Carlo paths. P5/P50/P95 scenarios. Real ticker volatility.
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