TL;DR: The daily loss limit caps how much equity you can lose in one day, measured on Propr from the 00:00 UTC realised balance, with open positions counted and a momentary touch enough to fail. In our replays of Propr's Classic and Pro 1-Step challenges at aggressive sizes, it ended far more attempts than the total drawdown limit (36% of starts versus 4% on the fastest Classic 1-Step plan). The fix is to budget a worst day, not an average one.
What is a daily loss limit in a prop firm challenge?
Many prop firm challenges have two loss rules. The maximum drawdown limits how far the account can fall overall. The daily loss limit limits how much it can fall within a single day. Break either and the attempt is over, whatever your profit so far.
On Propr, every 1-Step challenge has a 3% daily limit, and the Classic 2-Step has 5%:
| Challenge | Daily loss limit | Max drawdown | Profit target |
|---|---|---|---|
| Classic 1-Step | 3% | 6% static | +10% |
| Turbo 1-Step | 3% | 3% static | +9% |
| Pro 1-Step | 3% | 5% static | +12% |
| Classic 2-Step | 5% | 8% trailing | +10% total |
A 3% daily limit sounds generous until you notice it is half the total drawdown on the Classic 1-Step, and that it resets against a new base every day.
How is the daily loss measured?
Firms differ here, which is exactly why traders get caught. Propr's version:
- The base is the day's opening realised balance. At 00:00 UTC, Propr snapshots your realised balance. Your daily floor for the next 24 hours is that snapshot minus 3% of it. It is not measured from your initial balance.
- Equity is what is judged. Open positions count at their current value. A position down $250 counts as $250 lost, whether or not you close it.
- A momentary touch counts. If a wick takes equity under the floor for a second, the challenge is breached, even if price recovers immediately.
Because the base moves, so does the dollar limit. On a $10,000 Classic 1-Step, a day that opens at $10,400 allows $312 of loss; a day that opens at $9,600 has a $288 daily allowance, but the 6% static floor at $9,400 would end the attempt after a $200 loss.
When does the daily limit bind before total drawdown?
At aggressive sizes, when the drawdown floor is wider than the daily limit, because one day can hold a lot of risk. Total drawdown is a slow, cumulative test: you have to keep losing over many days to hit a 6% floor. The daily limit is a single-day test, and correlated positions, high leverage and a sharp market move can produce a 3% day without any warning.
Our replays show it clearly. We started a fresh challenge on every UTC day since 2023-07-24 for each of Trigr's house plans and ran each under Propr's exact rules for up to 365 days. Here is how failed starts failed:
| Plan | Failed by daily loss | Failed by drawdown |
|---|---|---|
| Classic 1-Step Fast | 36% | 4% |
| Pro 1-Step Fast | 30% | 12% |
| Turbo 1-Step Fast | 13% | 28% |
| Classic 1-Step Balanced | 2% | 11% |
| Pro 1-Step Balanced | 10% | 15% |
| Turbo 1-Step Balanced | 5% | 23% |
| Classic 2-Step Fast | 7% | 30% |
The pattern: at aggressive sizes on Classic and Pro, where the drawdown is wider than the daily limit, single bad days dominate. When sizing comes down to Balanced, daily breaches fall below drawdown breaches on both. On Turbo, where the 3% static drawdown is as tight as the daily limit, and on the 2-Step, with a 5% daily limit and a trailing floor, slow losses over several days are the bigger threat. Our trailing vs static drawdown guide covers that side.
A caution about these numbers: they are in-sample (the plans were chosen with the 2025 data visible), and overlapping start days are not independent tries. The pass rates that go with them, 58–100%, are far above what we measured out of sample (about 25–34%, with 40–55% as a planning figure for the slowest, smallest-size tier). The failure split is still a useful map of which rule bites first. The full picture is in prop firm challenge pass rates.
What happens to positions held across midnight?
This is the detail many traders miss. The 00:00 UTC snapshot is your realised balance, but the breach test uses equity. So a losing position held past midnight starts the new day already inside the new allowance.
Worked example on a $10,000 Classic 1-Step:
| Time | Realised balance | Open position P&L | Equity | Daily floor |
|---|---|---|---|---|
| 23:00 UTC | $10,000 | −$120 | $9,880 | (previous day) |
| 00:00 UTC snapshot | $10,000 | −$200 | $9,800 | $9,700 |
| 03:00 UTC | $10,000 | −$310 | $9,690 | $9,700: breached |
Measured from equity at midnight ($9,800), the trader lost only $110 on the new day, far less than 3%. But the floor was set from the realised balance, which did not include the $200 already lost, so the new day allowed only $100 more. The reverse is also true: an open winner at midnight gives you extra room, because equity sits above the realised base.
Practical options: close or reduce losing positions before 00:00 UTC, or count any open loss at midnight as already spent from the next day's budget.
Worked example: three correlated positions on one bad day
Suppose a $10,000 account, Classic 1-Step, three strategy slots on three different altcoins, each using a third of the account ($3,333) at 2x leverage, so about $6,667 notional each. Each has a stop 2% from entry. Round-trip costs are about 17 bps of notional.
| Per position | Amount |
|---|---|
| Loss at stop (2% of $6,667) | $133 |
| Round-trip costs (0.17% of $6,667) | about $11 |
| Total per position | about $144 |
| Three positions, all stopped the same day | about $433 (4.3%) |
On a day that opens at $10,000, the floor is $9,700. If the three coins drop together, which crypto alts often do, all three stops hit and equity reaches about $9,567. The challenge is over, even though no single trade lost more than about 1.4% of the account.
Now the same setup at 1x leverage (about $3,333 notional each): roughly $67 at the stop plus about $6 in costs per position, about $217 for all three, or 2.2%. That fits under 3% with about 0.8% to spare. The strategy did not change; only the worst-day exposure did. Our multi-strategy agent guide covers how slots combine.
How do you budget a worst day?
Use a simple sum and keep it well inside the limit:
worst-day loss ≈ (sum of notional × stop distance for every position that can be open at once) + (round-trip costs) + (any open loss carried over midnight)
Then check:
- Assume correlation is 1. Crypto perps that look unrelated in calm markets tend to fall together on bad days.
- Add a gap allowance. Stops are not exact. A fast move can fill beyond the stop, and the momentary-touch rule means a wick that reverses still counts. Our post on intrabar stops and take-profits explains why bar data can understate this.
- Watch leverage costs. At 10x, a round trip of about 17 bps costs about 1.7% of the account per trade. Two full-size round trips at that leverage cost more than a 3% daily limit in costs alone. Our best results came at 1–3x.
- Compare to history. The worst day in a backtest that replays every start date is a floor for your estimate, not a ceiling.
- Keep a buffer. A sizing that fits the worst historical day exactly is likely to breach live.
The position sizing guide turns this into a full sizing process.
Does respecting the daily limit raise your odds?
It removes a failure mode, but it does not create an edge. With no edge, the chance of reaching the target before the drawdown floor is about drawdown ÷ (target + drawdown), at most about 37.5% on the Classic 1-Step before costs, regardless of size. Shrinking size to stay off the daily limit lets the strategy's edge, if it has one, show up; it also makes the attempt slower. The odds math post covers this baseline.
How Trigr fits in
When you deploy your own agent on a Propr account (a house plan skips this step: Trigr shows the plan's measured record and sizes every slot itself), Trigr's rules check replays the combined backtest with a fresh challenge started on every UTC day, against that account's real daily-loss and drawdown rules, and reports the worst day as a percentage of the balance that day began with. If any start breached, you can press Optimize sizing, which shrinks positions over up to three re-runs per press until the backtest fits with a 0.5% margin under each limit. The replay measures a position held across midnight one day at a time, so a multi-day loser can breach live sooner than the replay shows; size with that in mind.
The house plans on Discover › Propr show each plan's failure split between daily loss and drawdown, so you can see which rule a plan is exposed to before you choose it. Setup is in the trading agents docs. If you take a Propr challenge, you can start one through our referral link.