5 Mistakes That Fail 80% of Prop Firm Challenges
Five mistakes that fail most prop firm challenges, written by people who watch the failure logs every day, with the fix for each one.
Rev One Trading3 min read
Psychology
Rev One
Five mistakes that fail most prop firm challenges, written by people who watch the failure logs every day, with the fix for each one.
We see the failure logs every day. Same five mistakes, in roughly the same order, account after account.
This isn't a list of trading mistakes (overtrading, no stops, FOMO). Those exist on every blog. This is the list of structural mistakes specific to prop firm challenges, which is where most traders actually fail.
The first thing a new challenge trader does is open the configurator and ask, "what's the cheapest account that lets me hit the target fastest?". That's sizing for the win.
The right question is: "what's the largest account where my normal stop is 0.5% to 1% of balance?". That's sizing for the loss.
A trader with a $200 stop on a $25K account is risking 0.8% per trade. That same trader on a $100K is risking 0.2% per trade. Same skill, two completely different failure rates.
For the contract math behind this, see micro vs mini futures.
The Max Loss Limit (MLL) is a hard breach line, not a stop. Hit it once, the account is gone. There's no "hover near it for a few days" on most firms.
Yet traders consistently size as if they have the full MLL to spend. On a $50K, that's $1,500. They take a $400 loss, then a $400 loss, then a $300 loss, and now they have $400 left for the rest of the eval.
The fix is a soft daily stop set at one third of MLL. On the $50K, that's $500. Hit it, walk away.
For how the MLL line actually moves, see trailing vs end-of-day drawdown.
The Rev One eval has no time limit. There is no "I have to trade today". Yet the data shows traders averaging 4 to 6 trades a day for the first two weeks of an eval, then collapsing.
Trade two days a week if your edge is in two specific setups that show up twice a week. The eval will wait. The 5-day minimum on the funded side is per cycle, not per week.
Look at the equity curve of a failed challenge. Nine times out of ten, there's a red day, then the next day's PnL is the largest absolute number on the chart, in either direction.
The red day did not cause the bust. The next day did. The trader sized up to "make it back", and the size was the bug.
The fix is mechanical: the day after a red day, your position size is halved. Not "felt", halved. Hold yourself to it for the rest of the eval.
The profitable-day rule on the eval is 3 days at 0.5% of balance. On the $50K, that's three days where closed PnL is at least $250.
Sounds easy. The data says otherwise: a meaningful percentage of traders hit the profit target without three qualifying profitable days, and have to keep trading just to stack the days. They're already at target. They oversize. They wash out.
Plan the profitable days from session one. Hit $250+ on three separate days early, before you even think about the target. Then the run to 6% is structural, not panicky.
For the rule mechanics, see the profitable day rule explained.
Before you start an eval, write a one-page plan with five lines:
Tape it to your monitor. Don't trade without reading it.
For the full pass framework, see how to pass a futures prop firm challenge in 2026.
Start the 1-step on the right sizeThe traders who pass don't have a special edge. They have a written plan that survives day three.