Maximum drawdown (MDD) is the largest peak-to-trough decline in an account's or portfolio's value over a specified period.
MDD = (Trough Value − Peak Value) ÷ Peak Value
If an account grew from ₹5,00,000 to ₹7,00,000, then fell to ₹4,20,000 before recovering, the maximum drawdown is (₹4,20,000 − ₹7,00,000) ÷ ₹7,00,000 = −40%.
Why Maximum Drawdown Matters More Than Returns
A strategy that returned 40% last year sounds attractive. The same strategy that returned 40% after experiencing a 60% drawdown tells a very different story — because most traders would have abandoned the strategy during the drawdown, locking in a 60% loss before the recovery occurred.
Maximum drawdown answers the question: how bad did it get, at worst? And the answer to that question determines whether a strategy is psychologically executable in live conditions.
The asymmetry of losses:
- A 10% drawdown requires an 11% gain to recover
- A 25% drawdown requires a 33% gain to recover
- A 50% drawdown requires a 100% gain to recover
- A 75% drawdown requires a 300% gain to recover
Large drawdowns are not just painful — they are mathematically difficult to recover from.
Interpreting Drawdown in Backtesting
When evaluating a trading strategy's backtest results, maximum drawdown is the primary risk metric. It defines:
The capital you need to survive: Your starting capital must be large enough that the maximum drawdown does not wipe it out or reduce it to a level where position sizing becomes impractical.
The psychological requirement: During the strategy's worst historical period, you would need to keep trading without deviation. For most traders, maximum drawdowns above 20–25% are psychologically unsustainable.
The risk-adjusted return: A strategy returning 30% annually with a 10% max drawdown is far superior to one returning 40% with a 50% drawdown — the second strategy risks ruin before the return is realised.
Calmar Ratio
The Calmar ratio divides annualised return by maximum drawdown: Return ÷ Max Drawdown. A strategy returning 20% with a 10% MDD has a Calmar of 2.0 — considered strong. Below 1.0 means the strategy earned less than it risked losing in its worst period.
Drawdown in F&O Accounts
F&O traders face an additional consideration: margin requirements. During a drawdown, a broker may issue a margin call requiring additional capital to maintain open positions. A trader who cannot meet the margin call is forced to exit at the worst point of the drawdown — the opposite of what a systematic recovery requires.
For educational purposes only. Profitma is not a SEBI-registered investment adviser or research analyst. Nothing in this article constitutes investment advice.