# Drawdown > The decline of an equity curve from its running peak, measured until a new peak is made; the maximum drawdown is the deepest such decline anywhere in the record. - Canonical: https://hadalinstruments.com/glossary/drawdown/ - Term set: https://hadalinstruments.com/glossary/ --- Drawdown is the distance below the high-water mark. It is a path statistic, not a return statistic: two strategies with identical return distributions can produce very different drawdowns depending on how their wins and losses happen to be ordered. That property is what makes drawdown informative — it measures the experience of holding the strategy, not just its average — and also what makes it treacherous to compare and easy to game. Two structural facts are routinely ignored. First, **maximum drawdown grows with track length**. Even for a strategy whose behaviour never changes, the deepest excursion observed over ten years will, in expectation, exceed the deepest observed over two — more history means more opportunities for a bad sequence. Comparing maximum drawdowns across records of different lengths without adjustment is comparing apples to a longer list of apples. Second, **backtested drawdown is biased shallow**. A configuration selected from many trials is selected partly for having dodged the historical data's worst sequences — a form of fitting to noise that [backtest overfitting](/glossary/backtest-overfitting/) produces automatically. The live drawdown distribution is systematically worse than the one in the pitch document, before anything about the market changes at all. Both halves are computable from a series you already hold: the [maximum drawdown calculator](/tools/maximum-drawdown-calculator/) reports the depth, the peak and trough behind it, the time under water, and whether the record ever recovered. Depth is also only half of the statistic. Drawdown duration — time under water, from peak to recovery — is frequently the operative number, because capital, patience, and mandates expire on the clock, not on the percentage. What converts drawdown from discomfort into termination is a barrier. Prop-firm loss limits, margin requirements, investor redemption triggers, and a trader's own capitulation point all place a hard floor under the equity curve; a statistical excursion that crosses the floor is not an excursion but an ending. That interaction — path statistics meeting hard barriers — is the domain of [risk of ruin](/glossary/risk-of-ruin/), and its sharpest practical form is the [trailing drawdown](/glossary/trailing-drawdown/) rule, where the floor itself moves. Where the depth above is a fact about a series that already happened, the [risk of ruin calculator](/tools/risk-of-ruin-calculator/) works forward from a win rate, a payoff ratio and a risk per trade to the probability of crossing a floor — and, because a win rate measured on a finite sample is an estimate rather than a constant, the range that sample actually supports. ## Commonly confused with Neighbouring concepts that get used interchangeably, and the distinction that actually separates them. - **Volatility** — Volatility describes the dispersion of returns without regard to their order. Drawdown is a path statistic: reorder the same set of returns and the volatility is unchanged while the drawdown can be transformed entirely. That is exactly why drawdown describes the experience of holding a strategy and volatility does not. - **Drawdown duration** — Depth and duration are separate statistics and the deeper one is not always the operative one. Time under water — from peak to recovery — is frequently what actually ends a position, because capital, patience and mandates expire on the clock rather than on the percentage. - **[Risk of ruin](https://hadalinstruments.com/glossary/risk-of-ruin/)** — A drawdown is an excursion; ruin is what an excursion becomes when it meets a hard floor. Loss limits, margin requirements, redemption triggers and a trader's own capitulation point convert a statistical dip into an ending. Drawdown describes the path; risk of ruin describes the path meeting a barrier. - **[Trailing drawdown](https://hadalinstruments.com/glossary/trailing-drawdown/)** — An ordinary drawdown is measured from a fixed running peak. Under a trailing rule the floor itself moves up with the equity curve, so gains permanently raise the level at which you are terminated. Same word, materially harsher object. ## How to measure it in your own data A definition you cannot test is a definition you have to take on trust. This is the shortest honest route from the concept to a number you computed yourself. - **Records you need** — An equity curve sampled at a consistent interval, together with the length of the record. The length is not optional bookkeeping — a maximum drawdown quoted without the period it was observed over is not a comparable number. - **What you compute** — Track the running peak, take the decline from that peak at every point, and record the deepest. Then compute the second statistic almost nobody publishes: the elapsed time from each peak to the recovery of that peak, and the longest such span in the record. - **What the answer tells you** — Compare only against records of the same length, because maximum drawdown grows with track length even for a strategy whose behaviour never changes — more history is more opportunity for a bad sequence. And treat any backtested figure as biased shallow: a configuration chosen from many trials was partly chosen for having dodged the worst sequences in that very data. ## Questions and answers ### Is maximum drawdown enough to compare two strategies? No, for two reasons that both cut the same way. Maximum drawdown grows with the length of the record, so comparing a ten-year track to a two-year one without adjustment is not a comparison. And depth omits duration — a shallower drawdown that lasts three years can end a mandate that a deeper one lasting three months would have survived. ### Why is my live drawdown worse than my backtest showed? Because the backtested figure was selected, at least in part, for having avoided the worst sequences in the historical data. Choosing a configuration from many trials fits the noise as well as the signal, and one of the things it fits is the particular ordering of good and bad periods in that sample. The live drawdown distribution is systematically worse before anything about the market has changed. ### What turns a drawdown into an actual failure? A barrier. A prop-firm loss limit, a margin requirement, an investor redemption trigger or a trader's own breaking point each put a hard floor under the equity curve. An excursion that crosses the floor is not an excursion — it is the end of the record. This is why drawdown tolerance is a function of your constraints and not only of the strategy. ### Does a strategy with no large drawdown in its history have low drawdown risk? Not necessarily, and short records are the trap. The deepest decline you have observed is bounded by how long you have been observing. A quiet two-year record and a genuinely shallow-drawdown strategy look identical until the record gets longer. ## If this has already cost you If a drawdown has already ended something, what your book would have done through a recorded shock can be replayed against the positions you actually held. - [Stress Replay Assay](https://hadalinstruments.com/assays/#stress-replay-assay) “What happens to my sizing when the market breaks?” Will not establish: The next shock. By construction the events that break books are the ones the sample did not contain, and the report carries that sentence rather than burying it. - [Prop-Breach Forensics](https://hadalinstruments.com/assays/#prop-breach-forensics) “Why did my prop evaluation actually fail?” Will not establish: Whether the firm’s rules are fair, or whether you would have passed with different luck. It reconstructs what happened; it does not adjudicate the firm. Intake is not open yet, so none of these can be commissioned today. They are listed here so you know the measurement exists and what it would and would not settle — the [launch list](https://hadalinstruments.com/pricing/#waitlist) hears first. ## Work it out yourself Free calculators that take this concept as an input. Each shows its working, so the number it gives you can be checked rather than taken on trust. - [Maximum drawdown calculator](https://hadalinstruments.com/tools/maximum-drawdown-calculator/) Depth, and the peak it fell from · Time under water - [Which drawdown rule do you have?](https://hadalinstruments.com/tools/trailing-vs-static-drawdown/) Five architectures, filtered · Floor under each reading - [Trailing drawdown calculator](https://hadalinstruments.com/tools/trailing-drawdown-calculator/) Floor and room · Room in pips at your lot size ## Related terms Derived from the links this entry makes and the entries that link back to it. - [Backtest Overfitting](https://hadalinstruments.com/glossary/backtest-overfitting/) The condition in which a strategy's historical performance reflects fitting to noise in a particular dataset rather than a persistent market effect, so that live performance regresses toward zero or below. - [Combinatorial Purged Cross-Validation (CPCV)](https://hadalinstruments.com/glossary/combinatorial-purged-cross-validation/) A backtest protocol that partitions a history into groups, holds out every combination of them in turn with purging and an embargo, and so produces many out-of-sample paths instead of a single one. - [Daily Loss Limit](https://hadalinstruments.com/glossary/daily-loss-limit/) A rule ending or suspending an account when losses within a single trading day exceed a set amount, assessed against a baseline that resets each day rather than against the account's overall decline. - [Hard Breach](https://hadalinstruments.com/glossary/hard-breach/) A rule breach whose stated consequence is the end of the account: the condition fires, the account is closed or its open positions are liquidated, and the programme is over subject to whatever the agreement says follows. - [High-Water Mark](https://hadalinstruments.com/glossary/high-water-mark/) The highest value an account has previously reached, held as a reference point so that a fee, a threshold or a termination floor is measured against the account's best moment rather than its starting value. - [Risk of Ruin](https://hadalinstruments.com/glossary/risk-of-ruin/) The probability that an account's equity reaches a barrier from which it cannot continue — margin exhaustion, a drawdown limit, or zero — before the strategy's edge has time to assert itself. - [Trailing Drawdown](https://hadalinstruments.com/glossary/trailing-drawdown/) A drawdown limit measured from an account's high-water mark rather than its starting balance, so that the termination floor rises as the account makes new highs and never retreats. ## Where the term is used Instrument pages whose published copy uses this term. Each page states what it measures and what it does not establish. - [Prop-Evaluee Risk Guardian](https://hadalinstruments.com/instruments/prop-evaluee-risk-guardian/) Drawdown-halt monitoring, sizing grids, risk-of-ruin surfaces, correlation-adjusted heat. Desk Discipline ## In the research Drawdown comes up in five research notes on this site, and this entry lists three of them. - [Why was my account breached in profit?](https://hadalinstruments.com/research/why-was-my-account-breached-in-profit/) An evaluation can end on a day that closed above its limit. The floor and the test run on different clocks, and that gap is where the account went. - [Is a drawdown limit on balance or equity?](https://hadalinstruments.com/research/is-my-drawdown-on-balance-or-equity/) The breach that surprises traders is computed on equity while they watched balance. How the definitions differ, why trailing limits bite, how to check yours. - [What causes a prop firm drawdown breach?](https://hadalinstruments.com/research/what-causes-a-prop-firm-drawdown-breach/) Rarely a losing streak. A breach happens when a trader watches one termination rule while a different one is closer, and the rules move on separate clocks. ## Cite This Definition APA BibTeX HTML Hadal Instruments. (2026). Drawdown. Hadal Glossary. https://hadalinstruments.com/glossary/drawdown/ Version edd6b92, 2026-08-31. @misc{hadal_2026_drawdown, author = {Hadal Instruments}, title = {Drawdown}, year = {2026}, url = {https://hadalinstruments.com/glossary/drawdown/}, howpublished = {Hadal Glossary}, version = {edd6b92}, note = {Pre-launch publication; version dated 2026-08-31} } Source: Hadal Instruments, Drawdown. Original Research Copy Citation **Version edd6b92** identifies the commit that last changed this page in Hadal's content repository. That repository is not public, so the identifier does not resolve externally — it is published so a citation pins one specific state rather than a moving page. To obtain the exact version cited, use the [press and research route](https://hadalinstruments.com/press/).