Maximum Drawdown

IntermediateRisk Management2 min read

Quick Definition

The largest peak-to-trough decline in portfolio value before a new peak is reached, measuring worst-case loss.

What Is Maximum Drawdown?

Maximum Drawdown (MDD) measures the largest percentage decline from a peak to a trough before a new peak is established. It represents the worst-case loss an investor would have experienced.

Formula: MDD = (Trough Value - Peak Value) / Peak Value × 100

Example:

  • Portfolio peaks at $100,000
  • Falls to $60,000 (trough)
  • Recovers to $110,000 (new peak)
  • Maximum Drawdown = ($60,000 - $100,000) / $100,000 = -40%

Why It Matters:

  • Shows actual worst-case experience
  • Tests psychological resilience
  • More intuitive than standard deviation
  • Indicates recovery requirement

Recovery Math:

DrawdownGain Needed to Recover
-10%+11.1%
-20%+25.0%
-30%+42.9%
-50%+100.0%
-75%+300.0%

Historical MDD Examples:

  • S&P 500 (2008-09): ~-56%
  • NASDAQ (2000-02): ~-78%
  • Average bear market: ~-30%

Uses:

  • Risk Assessment: Understand potential losses
  • Strategy Evaluation: Compare trading systems
  • Position Sizing: Size positions to survive MDD
  • Calmar Ratio: Return / Max Drawdown

Limitations:

  • Backward-looking (future could be worse)
  • Single data point (doesn't show frequency)
  • Time-dependent (longer history = larger MDD likely)

Formula

Formula

MDD = (Trough - Peak) / Peak × 100

Maximum Drawdown Example

  • 12008 financial crisis caused 50%+ drawdowns in many portfolios
  • 2Strategy with 20% max drawdown is more conservative than one with 40%