A drawdown measures the decline from a peak account balance to a subsequent trough before a new peak is established. It is the most important risk metric for traders and fund managers because it quantifies the worst-case scenario an investor has experienced. Maximum drawdown (MDD) is commonly reported alongside returns to give a complete picture of risk-adjusted performance.

The drawdown percentage is: Drawdown % = (Peak - Trough) / Peak x 100. The recovery percentage needed is: Recovery % = (Peak - Trough) / Trough x 100. The asymmetry of losses and gains is critical: a 50% loss requires a 100% gain to break even, while a 75% loss requires a 300% gain. This mathematical asymmetry is why risk management and drawdown control are paramount in successful trading.

For example, if your account peaked at $10,000 and dropped to $7,500, the drawdown is 25% ($2,500 lost). However, to recover from $7,500 back to $10,000, you need a 33.33% gain -- not just 25%. This is why experienced traders focus heavily on limiting drawdowns. A maximum drawdown of 20% is generally considered acceptable for most trading strategies, while drawdowns beyond 30% become increasingly difficult to recover from in a reasonable timeframe.