Maximum drawdown

Quick answer: Maximum drawdown is the largest peak-to-trough decline in account equity over a period, expressed as a percentage of the peak. Its defining feature is recovery asymmetry: a loss requires a proportionally larger gain to undo, so a 50% drawdown needs a 100% gain just to break even.

In simple words

Maximum drawdown is the worst drop your account took from a high point to a low point before recovering. If you were at a hundred and fell to seventy, that is a thirty per cent drawdown. The catch that surprises people is the maths of climbing back. Losing half your money does not need a fifty per cent gain to recover; it needs a hundred per cent gain, because you are now growing a smaller base. The deeper the hole, the more disproportionate the climb out. Depth is only half the story, though. What actually ends most trading careers is not how deep the drawdown went but how long it lasted, because time spent underwater drains conviction, capital and patience.

What the number measures

Maximum drawdown is the largest peak-to-trough decline in equity across a period, quoted as a percentage of the peak from which it fell. It is measured from a running high-water mark: every time equity makes a new high, the reference resets, and the drawdown is how far below that high the account subsequently sank before making the next new high. It says nothing about how long the fall took or how many separate losing trades caused it; it is purely the worst gap between a peak and the following trough. Because it is quoted against the peak, not the starting balance, it captures the felt experience of giving back gains as well as losing original capital. It is the single most cited measure of how much pain a strategy has historically inflicted.

The recovery asymmetry

The reason drawdown matters more than an equal-sized gain is arithmetic. After a decline of fraction d, the capital left is one minus d, and the gain needed to return to the peak is the peak divided by what remains, minus one — that is one over one minus d, minus one. The results are brutal and worth memorising. A 20% drawdown needs a 25% gain to recover. A 50% drawdown needs a 100% gain. An 80% drawdown needs a 400% gain. The gap between the loss and the required recovery widens without limit as the drawdown deepens, because each rupee lost must be regrown from a shrunken base. This is why capping drawdown is structurally more valuable than chasing return: the deep hole is not merely twice as bad as the shallow one, it is disproportionately worse.

Duration is what ends careers

Depth gets quoted, but duration does the damage. Time under water — the stretch between the old peak and the eventual recovery to a new high — is what actually removes traders and funds. A 15% drawdown that recovers in a month is a footnote; a 15% drawdown that grinds on for two years tests whether the trader keeps funding the account, whether investors stay, and whether the strategy is quietly broken rather than merely unlucky. Prolonged drawdowns erode the two things a trader needs to reach the eventual recovery: capital, drained by living costs and margin, and conviction, drained by the daily experience of being wrong. Many strategies do not fail at their maximum depth; they fail because nobody could hold them long enough to see the trough become a recovery.

It is a sample statistic

Maximum drawdown is the worst decline that has happened so far in the data you are looking at — a sample statistic, not a limit. The true worst case has not occurred yet, almost by definition, because a longer or unluckier sample would contain a deeper trough. Treating a historical maximum drawdown as a ceiling is a category error: it is the largest of the losses observed, not the largest possible, and the next one can exceed it. This is especially dangerous with strategies whose losses are rare and large, where the sample may simply not yet contain the event that defines the real risk. A quoted maximum drawdown should be read as a lower bound on how bad things can get, not an upper one.

Leverage multiplies it for free

Leverage scales every return, up and down, by the same factor, but it does not scale expectancy — the edge per rupee of risk is unchanged. What it does change is the drawdown, which it multiplies directly. Double the leverage and the drawdown path roughly doubles, pushing the account deeper into the region where the recovery asymmetry turns vicious and where the floor that defines ruin comes into reach. Because the recovery requirement grows faster than the loss, a leverage-amplified drawdown is harder to recover from than the extra return justifies. This is the quiet trap of leverage on a positive-edge strategy: it adds nothing to the long-run edge per unit of risk while multiplying the depth and duration of the holes along the way, and the holes are what remove you before the edge compounds.

Common mistakes

• Reading maximum drawdown as the worst that can happen treats a sample statistic as a hard limit, when a longer or unluckier run can always produce a deeper trough than the data has shown so far.
• Assuming a loss and its recovery are symmetric leads to under-estimating the climb back, because a 50% fall needs a 100% gain, not a 50% one, and the gap only widens with depth.
• Judging a strategy only by drawdown depth ignores duration, yet it is the years spent under water, not the depth itself, that drain the capital and conviction needed to reach the recovery.
• Adding leverage to lift returns multiplies the drawdown while leaving expectancy per unit of risk unchanged, so it deepens the very holes that the recovery asymmetry makes hardest to escape.
• Comparing two strategies by return without comparing their drawdowns hides the fact that the higher-return path may be unreachable, because no one could hold its deeper, longer drawdown to completion.
• Sizing a position off a historical maximum drawdown assumes the future cannot exceed the past, which is precisely the assumption that fails when the rare, defining loss finally arrives.

Professional usage

Funds treat maximum drawdown as a first-class risk limit, often more binding than any return target. Investment mandates and prime-broker terms frequently specify a maximum-drawdown trigger that forces de-risking or a stop-out, so the number is not merely descriptive but contractual. Risk teams monitor both depth and time-under-water, model drawdown paths with simulation rather than trusting the historical maximum, and size positions so that a stress scenario keeps the projected drawdown inside the mandate. Because the recovery asymmetry makes deep holes structurally expensive, institutions generally prefer smoother equity curves at lower headline return over jagged ones at higher return. Retail traders have no external drawdown mandate forcing discipline, and no committee to cut them, which is exactly why importing an explicit drawdown limit — a level at which size is cut regardless of conviction — is one of the few institutional practices that transfers cleanly.

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Last reviewed 9 July 2026. Educational content only — not investment advice.