Drawdown is the percentage decline from a recent equity peak to the lowest point that follows. It’s the most underrated number in trading performance, because traders tend to fixate on total profit and forget that how the account got there — smoothly or violently — is what actually determines whether they survive long enough to keep that profit.
How to calculate it, and why the math isn’t symmetric
Drawdown = (Peak equity − Trough equity) / Peak equity × 100%. Account peaks at $10,000, drops to $7,000 — that’s a 30% drawdown.
The part most traders miss: recovery math isn’t symmetric with loss math. A 30% loss needs a 43% gain to get back to breakeven (7,000 → 10,000 is +42.8%). A 50% loss needs a 100% gain. A 70% loss needs upward of 230%. That curve isn’t linear — the deeper the drawdown, the more unrealistic the required recovery gets, and plenty of traders never come back from a drawdown past 50% because the psychological pressure to “win it back fast” pushes them into bigger, riskier positions — the exact behavior that made the original drawdown worse.
Two kinds of drawdown worth separating
Maximum drawdown (MDD) is the single deepest decline recorded across the entire account history — the number that tells you the worst case a strategy has actually produced.
Current drawdown is how far below the most recent peak you’re sitting right now. This is the number to watch daily, because it tells you where you are in the account’s cycle — near a high, in a mild dip, or deep enough to require action.
Plenty of traders only ever look at MDD in a backtest report and never track current drawdown while live trading — which is exactly why they don’t notice they’ve blown past their own risk limit until the account is already down 35-40%.
Setting a realistic drawdown limit
A drawdown limit is the maximum loss percentage you allow before you’re forced to stop trading, cut size, or re-evaluate the whole system. For an individual trader running their own account, reasonable tiers look something like:
- 10-15%: warning threshold — cut size by half, review the last week of the journal.
- 20%: stop threshold — pause trading for at least a few days, figure out whether the system is genuinely failing or this is normal variance within its expected range.
- 25-30%: emergency threshold — stop entirely, revisit the strategy from scratch, don’t reopen the account until you have a clear explanation for the drawdown and a concrete plan to avoid repeating it.
Prop trading firms set far tighter limits — daily drawdown of 4-5%, max drawdown of 8-10% — because they’re managing capital that isn’t theirs and need a much wider safety margin than someone trading their own money.
Why a system with positive expectancy can still drawdown hard
This trips people up constantly: a system with genuinely positive long-run expectancy can absolutely go through a losing streak that produces a sharp short-term drawdown, purely from probability. With a 40% win rate system, the odds of hitting a 5-trade losing streak somewhere in a 100-trade sample aren’t small at all. If position size isn’t tightly controlled — risking 3-5% of the account per trade instead of 1%, say — a statistically ordinary losing streak can turn into a 20-25% drawdown in a week or two.
This is why position sizing matters just as much as picking the right setup. A good strategy with the wrong size can still blow up an account, while a mediocre strategy with disciplined sizing survives normal losing streaks just fine.
Controlling drawdown starts before it happens
The most effective way to control drawdown isn’t reacting once it’s already deep — it’s limiting it by design: fixed risk of 0.5-1% of the account per trade, a cap on concurrent open positions, and one hard rule — never increase size to “win back” a drawdown while inside one. Treating current drawdown as a live number you check daily, not something you only glance at during a monthly review, is the only way to step in before 15% turns into 40%.
More on this in the Trading performance section.