Every challenge account has a cause of death, and it's written on the certificate before you start trading. It is almost never "bad analysis." It's one of three floors, and most people can only name one of them.
Three floors, not one
The maximum drawdown is the one everyone knows: a hard limit under the whole run. Simple, static, survivable — you'd have to be genuinely reckless over a sustained period to find it first.
The daily floor is the one that does the killing. It only asks for one bad session. It resets every day, which reads like generosity and is actually the mechanism: a fresh budget every morning is an invitation to spend it, and the rule only has to catch you once.
The trailing floor is the one that isn't fair, in the sense that "fair" is a thing you assumed and nobody promised. It ratchets upward underneath every new equity high you print. Run the account to +6%, and the floor comes up behind you. Give back 5% and you may be in breach — while the account is still up on the run.
Read that again, because it's the single most expensive misunderstanding in this business. Under a trailing floor, profit you made and returned is counted against you. You are not being measured from where you started. You are being measured from the best moment you ever had, which is a rule with an unpleasantly biographical quality to it.
The arithmetic nobody runs before paying
Here's the number that should reorganise your plan. Losses do not cost what they appear to cost, because you repay them out of a smaller account.
- Lose 5%, and you need about 5.3% to get level.
- Lose 10%, and you need about 11.1%.
- Lose 20%, and you need 25%.
- Lose 33%, and you need 50%.
The gap widens the deeper you go, and it widens fastest exactly where a challenge account lives. Now put that beside the structure from lesson one: you need +10% to pass and −10% ends you. If you dig yourself down 6% early, you don't need 16% to pass. You need 17%, from a smaller base, with only 4% of floor left underneath you and a daily limit that hasn't gone anywhere.
That's the whole trap. A drawdown doesn't just cost you money — it costs you room, and room is the thing you're actually trading. The plan that survives is the one that never gets deep, not the one that's good at climbing out.
Where the real breaches come from
Almost every breach we've heard described falls into one of four buckets, and none of them are exotic:
- Reset confusion. The trader thought the day rolled at midnight local. It rolled at 5pm New York, or at server time in a timezone they never checked, and two sessions got counted as one with a single shared loss budget.
- The trailing floor surprise. Covered above. Almost always the first time that trader ever traded a trailing account.
- Sizing that never got revised. A position size chosen when the account was flat, still running after the account was 5% down and the remaining room had halved.
- The recovery push. Down on the day, size up to fix it, find the floor faster. This is lesson four's territory, and it's the most human of the four.
Notice what's absent from that list. Nobody breaches because their strategy stopped working. Strategies decay slowly and visibly. Floors are found suddenly and by arithmetic.
Next: position sizing — the single number that decides whether any of these floors can ever reach you, and why three ordinary bad days is the entire budget you're working with.