your prop account doesnt kill your strategy, it kills your path
ran the same strategy on my own account and on a funded account for a while. same entries, same exits, same everything. own account was fine. funded one breached. took me embarrassingly long to work out why, because the trades were identical.
its the path, not the result.
on a trailing drawdown account your floor follows your equity peak. on intraday trailing that includes the peak of an open position. so when a trade runs +30 in your favour and comes back to stop out at -20, your buffer didnt lose 20. the peak at +30 dragged the floor up first. what actually hit your buffer was closer to the full 50 point swing.
which means the risk unit on a trailing account isnt your stop. its your stop plus whatever open profit you typically give back before exit.
thats why every position size calculator flatters you. they size from stop distance and closed pnl, so they tell you the account survives ten losses when the real number on the path you actually travel is more like four or five. its not a rounding error, its a completely different number.
and it explains something that used to make no sense to me. trades that closed green were still costing me buffer. a winner that goes +40 and closes +10 has moved my floor up 40 and given me 10. on my own account thats a nice day. on a trailing account thats a net drain on my room to be wrong later.
the fix isnt a better strategy, its sizing off the right unit. pull the MFE on your losing trades, take the median, add it to your stop. thats what a loser really costs you on an intraday trailing account. resize from that number and the account stops feeling randomly hostile.
eod trailing is softer since the floor only ratchets at the close, so the same system can be viable at one firm and structurally unsafe at another with identical rules on paper. worth knowing which type youre actually on before blaming the strategy.
i run my exports through a script that pulls the MFE giveback and recalculates the real survivable streak, took ten minutes to see something id been missing for months. anyone else sized off MFE rather than stop, or is everyone still using the calculators