How to size a strategy against trailing drawdown
Trailing drawdown ends more funded accounts than bad trades do. The fix isn't a better signal — it's sizing that respects how the floor moves. Here is how to do it on an end-of-day vs intraday trailing account.
⚠ Rules change often. Prop-firm rules and drawdown models change frequently. Always verify the firm's current Terms of Service before deploying any strategy. Figures here were checked May 2026.
A trailing drawdown is a floor that rises with your equity highs and never falls back. Make new profit and the floor follows you up; give it back and the floor stays put. So the number that matters isn't your balance — it's your distance to the floor, and that distance only shrinks.
Step 1: know which floor you have
Two models change everything. End-of-day (EOD) trailing only re-marks the floor at session close, so intraday dips are survivable. Intraday trailing re-marks on every tick, including unrealized highs — a 10-point run that gives back 6 still moved your floor by the full 10. Read EOD vs intraday first.
Step 2: size from the floor, not the balance
Pick a per-trade risk that is a small fraction of your distance-to-floor, not of account size. On a $50K account with a $2,500 trailing drawdown you are really trading $2,500 of room. Risking $250 per trade is 10% of your real buffer — two losers and a bad fill and you are in trouble. Conservative systematic sizing keeps each trade well under that.
Step 3: respect the asymmetry on intraday floors
On intraday trailing, scaling out or letting winners run raises the floor permanently. That is why aggressive sizing belongs only on EOD accounts. The same strategy that thrives on an EOD floor can breach an intraday one mid-trade — nothing changed except the floor logic.
Why a hardcoded system has the edge here
Discretionary traders move size with emotion, which is exactly what blows the buffer. A rules-based system uses the same fixed risk every time and, on the futures presets, an end-of-day guard that flattens before the close so the EOD mark lands where you expect. Puravida Edge ships a Conservative preset for any trailing model and an Aggressive one for EOD-only accounts — matched to the firm, not guessed.
To see modeled time-to-pass and blow rate for a given size and floor, run the Pass Estimator, or read why accounts blow on green days.
FAQ
What is trailing drawdown in simple terms?
A loss limit that rises with your equity highs and never comes back down. Your real risk is the distance between your balance and that floor, and it only shrinks.
How much should I risk per trade with a trailing drawdown?
A small fraction of your distance-to-floor, not of account size. On a $50K account with a $2,500 trailing limit, you're trading $2,500 of room — keep per-trade risk well under 10% of that.
Is aggressive sizing ever safe with trailing drawdown?
Only on end-of-day trailing accounts, where intraday dips don't move the floor. On real-time/intraday trailing, aggressive sizing risks breaching the floor mid-trade.
Does scaling out help or hurt on trailing drawdown?
On intraday trailing it can hurt: every new equity high permanently raises the floor, even highs you give back. On EOD trailing only the closing mark counts.
Not financial advice. Performance figures referenced are hypothetical, modeled outputs (1,500-path Monte Carlo on a 12-month sample). Past performance does not guarantee future results. Prop-firm Terms of Service compliance is your responsibility — verify every rule with the firm directly.