How it works

Enter the account's trailing room (the gap between your balance and the trailing floor) and your strategy's 95th-percentile interim drawdown per contract from a Monte Carlo on your own trades. The tool returns the largest whole size whose drawdown still fits inside the room. A prop combine is a variance test, not a profit test, so size to the floor, not to the target.

Worked example

Our NQ book has a 95th-percentile drawdown of about $6,300 per micro against the $50k TopStep Combine's $2,000 of room, roughly three times the room. That is why a strategy with a 15-year positive record still fails the cheapest combine on a normal losing stretch. The full method is in why profitable traders fail prop firm combines.