Maximum drawdown describes the largest decline from a prior peak to a later trough in a specified account-value series. It is a historical measurement of a path, not a limit that the next trade must obey. A strategy's future decline can exceed its observed backtest or live-account drawdown.
Before comparing two percentages, identify the measured series, observation frequency, dates, currency and treatment of deposits. A daily balance series and a continuously observed equity series can tell very different stories about the same trades. The numbers below are invented examples for learning the calculation, not Quantora account results.
Keep a running peak and calculate each decline
For a simple cash-flow-free series, keep the highest value seen so far. At each later observation, monetary drawdown = running peak minus current value. Percentage drawdown = that difference divided by the running peak, multiplied by 100. A new high resets the running peak; a temporary recovery below the high does not.
Consider values of $10,000, $11,000, $9,900, $10,500 and $8,800. The $11,000 peak remains the comparison point for the last three values. Their declines are 10%, approximately 4.55% and 20%. The maximum observed percentage decline is therefore 20%, while the $2,200 peak-to-trough monetary decline is not measured from the original $10,000 deposit.
| Account value | Running peak | Decline from peak |
|---|---|---|
| $10,000 | $10,000 | 0% |
| $11,000 | $11,000 | 0% |
| $9,900 | $11,000 | 10% |
| $10,500 | $11,000 | 4.55%, approximately |
| $8,800 | $11,000 | 20% |
Balance can conceal open losses
Balance reflects booked account activity, while equity incorporates the current value of open positions and applicable account adjustments. An account can show a $12,000 closed balance while open losses reduce equity to $9,000. Against a prior $12,000 equity peak, that is a 25% equity decline even if the displayed balance has not yet fallen.
For a grid, a growing open basket can create exactly this distinction. Review equity, total volume and remaining margin alongside closed-trade growth. MetaTrader tester reports present separate balance and equity drawdown measures; do not combine them or assume a smooth balance curve describes the experience of holding the trades.
The recovery percentage uses a smaller denominator
After a 20% decline, an account worth $10,000 becomes $8,000. Returning to $10,000 requires $2,000 divided by $8,000 = 25%, not 20%. More generally, recovery fraction = loss fraction divided by one minus the loss fraction, provided the account has not fallen to zero.
A 50% decline needs a 100% gain to regain the original value. A 75% decline needs 300%. These calculations explain the asymmetry; they do not predict that a strategy will recover or how long recovery might take. Additional deposits restore cash but do not transform a losing trading period into a profitable one.
Cash flows and observation frequency need disclosure
A withdrawal can reduce an account value without being a trading loss, and a deposit can conceal a decline if raw values are compared without adjustment. State whether the analysis uses raw equity, a unitised return series or another explicitly described cash-flow method. Do not apply the simple no-cash-flow example blindly to statements with transfers.
Daily snapshots can also miss an intraday trough. A report sampled once after market close may show a smaller maximum drawdown than a tick-by-tick record. Missing data, chart resolution and the exact reporting method matter. Comparing percentages from different platforms requires more than matching the label drawdown.
Connect the historical path to present exposure
Record maximum drawdown with its duration, recovery period, largest loss, trade count, market conditions and position-sizing rule. A 10% drawdown achieved at one lot schedule does not establish the same result after doubling volume or adding another correlated system.
As a separate stress exercise, suppose four equal cash losses of $100 occur while the account has $2,000 equity and no other adjustments. The resulting $400 decline is 20% of that starting equity. If an EA adds positions before exiting, the losses need not remain $100 each. Model the full basket and an adverse execution case rather than multiplying a conveniently small first-order estimate.
A review checklist for backtests and live records
- Name the series: balance, equity or adjusted return index, including the sampling interval and date range.
- Describe deposits, withdrawals, credits and account-currency changes rather than silently excluding inconvenient records.
- Save original settings, maximum positions, volume progression, commission and financing assumptions.
- Compare drawdown duration and open exposure with the headline return and win rate.
- Keep an untouched test period and inspect losing regimes; a historical minimum decline is not proof of future protection.
- Treat your written exposure and exit limits as decisions to verify operationally, not as guarantees that all exits fill at the requested price.
Common questions
- Is maximum drawdown the same as one losing trade? No. It measures a decline along an account-value path and can include many trades or floating losses.
- Does a basket stop cap loss exactly? A local rule can depend on a running terminal, and execution can exceed the threshold. Inspect the actual implementation.
- Can a shorter record have lower drawdown? Yes. It may simply omit a difficult regime or contain fewer observations; age and conditions belong beside the percentage.