Nearly every prop firm blow-up comes down to a trader knowing they had "a 10% drawdown" and nothing more precise than that. There are two drawdown rules on almost every evaluation, they measure different things, they reset on different schedules, and the one that gets people is rarely the one they were watching. If you only remember one idea from this, make it that: you are being tracked against two limits at once, and you have to stay clear of both, all the time.
The two limits, plainly
The daily loss limit is the most you are allowed to lose in a single trading day. On a typical account it sits around 5% of your starting balance. Cross it and the account is done, regardless of how healthy your overall equity looks. It resets at a fixed server time and starts fresh each day.
The maximum loss limit (also called overall or total drawdown) is the most you are allowed to lose across the entire evaluation, measured from a fixed reference point. On a typical account it sits around 10%. This one does not reset. It is the floor beneath the whole account for as long as it exists.
Think of them as two clocks. The daily limit is a sprint timer that resets every session. The max limit is a countdown that only ever moves one way toward zero unless your strategy claws equity back. You can be comfortably clear of one and a single tick away from the other.
Why the daily limit catches people first
The daily limit is deceptively easy to breach because most traders measure it against the wrong number. It is usually calculated from your balance or equity at the start of the trading day, whichever your firm specifies, and crucially it counts floating losses in real time. That means an open trade that is 4% underwater has already spent 4% of today's budget, even if you have not closed anything and fully intend to let it run to your stop.
Here is the trap. A trader takes a loss of 2%, then another of 2%, and thinks "I am at 4%, I still have room." They open a third position sized as if the day were fresh. It moves against them by 1.5% before their stop, the platform measures equity in real time, and the account breaches at 5.5% intraday even though they planned for the trade to lose only 1.5%. The daily limit does not wait for you to close. It watches your equity every second.
Where the daily line is measured from
Firms differ on the reference point, and it matters. Some anchor the daily limit to your balance at the day's open. Some anchor it to your equity at the day's open, which can be higher if you were holding a winning trade overnight. Some take the higher of the two. A few move the reference intraday. Read your firm's definition word for word, because a 1% difference in where the line sits is the difference between a passed challenge and a voided one.
Why the max limit is the quieter killer
The maximum loss limit fails traders slowly, over a bad week rather than a bad hour. Three or four mediocre sessions, none of them breaching the daily limit, can walk your equity right down to the max floor. Because no single day felt catastrophic, the trader never registers the cumulative danger until they are almost out of room. This is the limit that punishes a strategy with a low win rate and long losing streaks, even when its expectancy is positive.
How the max limit is measured is where things get genuinely tricky, because it comes in two very different flavours. A static max loss is anchored to your initial balance and never moves. A trailing max loss follows your equity or balance upward as you make new highs, which quietly tightens the floor beneath you the moment you become profitable. Two accounts can both advertise "10% max drawdown" and behave nothing alike. This distinction is important enough that it deserves its own read: see trailing vs static drawdown for exactly how a trailing floor can breach an account that is still in profit.
The interaction that actually ends accounts
The two limits are not independent, and the fatal mistake is managing them one at a time. Consider a trader on a trailing max drawdown who has pushed the account to a new high. Their trailing floor has ratcheted up close behind their equity. Now they have a red day. The daily limit gives them 5% of room, so they use most of it, thinking that is the only constraint that applies today. But the trailing max floor is sitting far closer than 5% below them, so they breach the overall limit long before the daily one, on a day they considered normal. They were watching the sprint timer while the countdown ran out.
The habit that prevents this is simple to state and hard to practise. Before every trade, check your distance to both lines and size for whichever is closer. Some days the daily limit is the binding constraint. Some days, once you are in profit on a trailing account, the max floor is. Your position size should answer to the nearer of the two, always.
Turn the limits into a number you watch
Abstract percentages do not change behaviour. A concrete, live figure does. The single most useful thing you can put in front of yourself while trading a challenge is your current distance, in money and in percent, to each limit. "I have 380 dollars of daily room and 1,900 dollars to the max floor" is a sentence that keeps you honest in a way that "I'm allowed a 5% daily loss" never will.
This is exactly the kind of metric that belongs in your tracking, alongside the usual expectancy and R-multiple work. If you are building out what you monitor, our guide to the trading journal metrics that actually matter covers how distance-to-limit sits next to the performance numbers. TradeSave+ prop-firm account journals compute both drawdown distances for you as trades close, so the binding constraint is always on screen rather than something you reconstruct in your head halfway through a losing day.
The short version
Two limits, two clocks. The daily one resets and counts your floating losses in real time, so it catches impatience. The max one never resets and can trail up behind your profits, so it catches complacency. Traders fail not because the rules are unfair but because they manage one limit and forget the other exists. Watch both, size for the nearer, and most of the ways a prop account dies simply stop being available to you. If you want the full playbook for stringing safe days together into a pass, the challenge survival guide picks up where this leaves off.