Max Drawdown Explained: The Number That Sizes Your Risk

Most traders obsess over their win rate and their best month. Max drawdown is the number that actually decides whether you're still trading next year. It measures the worst stretch your account has been through — and it's the honest answer to the question "how bad does this get?"

What max drawdown actually is

Max drawdown is the largest peak-to-trough decline in your account equity, measured from a high-water mark down to the lowest point before a new high is made. It's usually quoted as both a dollar figure and a percentage.

The key word is peak-to-trough. It isn't your worst single trade, and it isn't the difference between where you started and your lowest point. It's measured from the top of an equity high down to the bottom of the valley that follows, before your equity climbs back above that old high.

Your equity curve makes a new high, then slides. The gap between that high and the lowest point it reaches before recovering is a drawdown. Your max drawdown is simply the deepest one on record.

A worked example

Say your account climbs steadily to a peak of $12,000. That's your high-water mark. Then a losing streak hits. You give back trades until your equity bottoms out at $9,600 before you finally string together some winners and start climbing again.

That valley is your drawdown:

• Peak: $12,000
• Trough: $9,600
• Dollar drawdown: $12,000 − $9,600 = −$2,400
• Percentage drawdown: $2,400 / $12,000 = −20%

If, later, your account runs to $15,000 and then dips to $13,200 (−12%), that's a smaller drawdown. Your max drawdown stays at −20% until something deeper comes along. It's a running worst-case, not a rolling one.

Why it matters, part one: the pain you have to survive

A −20% drawdown doesn't feel like a line on a chart when you're living it. It's weeks — sometimes months — of watching your account bleed while every setup you take seems to fail. This is where traders blow up: not from one bad trade, but from abandoning a working system three trades before it recovered, or from doubling size to "make it back" and turning a −20% dip into a −45% hole.

Your max drawdown is a preview of the emotional load you're signing up for. If you can't imagine sitting through a stretch that deep without panic-sizing or quitting, your strategy is too aggressive for you — regardless of what the backtest says.

Why it matters, part two: it sizes your positions

This is the practical payoff. Your drawdown tells you whether your position sizing is survivable.

Here's the trap: a strategy can have a great expectancy and still ruin you if you size so large that a normal drawdown wipes you out. The goal isn't to avoid drawdowns — they're guaranteed. The goal is to size so that a routine drawdown is an inconvenience, not a funeral.

If your historical max drawdown is −20% at a given risk-per-trade, and you double your risk per trade, you should expect that drawdown to roughly double too. Now you're staring at −40%, and the recovery math gets ugly fast.

The recovery math nobody wants to hear

Drawdowns are asymmetric. The percentage you lose and the percentage you need to recover are not the same number, and the gap widens the deeper you fall:

Drawdown	Gain needed to recover
−10%	+11%
−20%	+25%
−33%	+50%
−50%	+100%
−75%	+300%

Read the −50% row twice. If you lose half your account, you don't need a 50% gain to get back — you need to double what's left. A $10,000 account down to $5,000 has to earn 100% just to reach even. That's why deep drawdowns are so lethal: they don't just cost you money, they cost you the mathematical ability to recover in any reasonable timeframe.

Shallow drawdowns are cheap to climb out of. Deep ones can end a career even when your edge is still intact.

The drawdown you've seen vs. the one you haven't

Here's the mistake that gets disciplined traders: treating your historical max drawdown as your worst possible drawdown. It isn't. It's just the worst you've experienced so far.

If your record shows a −20% max drawdown over 300 trades, the honest planning assumption is that your true worst-case is deeper — you simply haven't hit the bad-luck cluster yet. A useful rule of thumb: plan for a drawdown roughly 1.5x to 2x your observed max. Size your account so that even a −35% or −40% stretch leaves you funded, calm, and still in the game.

You want to be pleasantly surprised by how shallow your drawdowns stay, not blindsided by one you swore couldn't happen.

How consecutive losses feed the drawdown

Drawdowns are usually built from losing streaks, and streaks are more common than intuition suggests. If you risk 1% per trade and take six losses in a row — which happens regularly even at a 50% win rate — you're down roughly 6% before you win anything. Ten in a row and you're near −10% from clustered losses alone.

This is why understanding your losses in R terms matters. If your average loss is 1R, a string of consecutive losers translates directly into R-multiples of drawdown, and you can stress-test how a realistic bad streak maps onto your equity curve before it actually happens.

Drawdown and prop-firm rules

If you trade a funded account, drawdown stops being advice and becomes a hard rule. Most prop firms enforce a maximum trailing or static drawdown — breach it and the account is gone, no appeal. That constraint should dictate your sizing from trade one, because a prop drawdown limit is far tighter than the pain threshold you'd set for yourself. We cover how to size against those limits in position sizing for prop firms.

Track it so you can respect it

You can't manage a number you don't measure. The whole point of a journal is to know your real drawdown — not the sanitized one from a backtest, but the one your actual trading produced, with your actual hesitation and revenge trades baked in.

Sutekka builds your equity curve from your logged trades and surfaces your max drawdown automatically, so you can size to survive the drawdown you haven't had yet instead of the one you're hoping for. Sutekka tracks your drawdown so you can size to survive it — start free.