Use case · Prop firms
Practise a Prop Firm Challenge Before You Pay for One
A prop firm challenge is a paid exam with rules you can fail on a single bad day. Most traders find out whether their strategy survives those rules by buying an attempt and discovering the answer in real time, at real cost. There is a cheaper order of operations: test it against the rules first, on history you can replay as many times as you need.
The rules are what fail people, not the strategy
Most challenge rulebooks share the same shape: a profit target, a maximum daily loss, and a maximum overall drawdown, usually with a minimum number of trading days. Traders fixate on the profit target, but the target is rarely what ends the attempt. The drawdown limits are.
That distinction matters because it changes what you need to know about your strategy. A method with a good win rate and a brutal losing streak can hit the profit target comfortably in a normal month and still breach a daily-loss rule in a bad week. The question is not "is this profitable" — it is "does this stay inside the rules while it gets there", and that is a different measurement.
You can put a number on that before committing to anything. The prop firm challenge calculator takes a rulebook's profit target, daily loss limit and maximum drawdown alongside your own win rate and average R, simulates thousands of attempts, and reports how often each of the three finish lines comes first.
What to measure before you pay
Four numbers decide whether an attempt is realistic, and all four come from a large enough sample rather than a feeling. Your win rate and average R tell you whether the target is reachable at all. Your longest losing streak and worst peak-to-trough drawdown tell you whether you would still be alive when it happened.
Run the numbers against the specific rules you would be trading under. If your worst historical drawdown is larger than the account's maximum, the attempt fails on arithmetic before you place a trade — and no amount of discipline fixes that. Size each test properly with the position size calculator so the drawdown you measure is the one you would actually take, then feed the measured win rate and average R into the prop firm challenge calculator to see the pass rate they imply — and which risk per trade gives you the best odds under those rules.
Margin is worth a separate glance, because on a funded account it is almost never the thing that fails you. The evaluation's daily-loss and drawdown limits breach long before a broker's stop-out is in sight — the margin and leverage calculator makes that gap concrete, and shows the effective leverage a given size actually puts you at.
Why replay beats a demo attempt
Demo trading a challenge in real time takes as long as the challenge does, and gives you one sample of one market period. Replay compresses that: you can put a strategy through months of history in an afternoon, including the conditions that would have broken it — the choppy stretch, the news-driven gap, the losing run.
It also removes the temptation to grade yourself generously. Because the next candle has not printed, you cannot quietly skip the trade you would have taken live. That is the difference between a test and a rehearsal, and it is covered in more detail in the backtesting mistakes that make results worthless.
Prop firm mode does the marking for you
This is a built feature rather than a discipline you have to impose on yourself. Switch prop firm mode on and the session becomes an evaluation: you set the profit target, the maximum drawdown and whether it is a one-step or two-step challenge, and the chart tracks the run and delivers the verdict. The defaults are the industry-normal shape — 8% target, 5% on phase two, 10% max drawdown — and every number is editable before the session and during it.
Two details in there are the whole reason it is worth using rather than eyeballing. The profit target is measured on closed balance, because a firm marks a challenge on realised equity and a floating winner you have not banked has not passed anything. The drawdown is measured on live equity — balance plus the open position — so a breach happens the moment price prints through the floor, not when you get round to closing. Anything softer teaches a habit that blows a real account.
Passing phase one resets the balance rather than carrying the profit forward, which is how every two-step evaluation on the market works and which makes phase two a genuine second test instead of a formality you are already most of the way through.
You can also choose how the loss limit behaves: static, measured from the balance the phase started at, or trailing, measured from the highest equity the run has reached so the floor follows you up and never comes back down. Firms sell both, and traders routinely buy a trailing challenge without having ever tested against one. Running the same strategy under each is a twenty-minute exercise that has saved people an entry fee.
Pick your market, drop into real history, and trade forward one candle at a time under your actual rules — same risk per trade, same daily stop, same target. Log every outcome. After a few hundred trades you have a real distribution instead of an intention, and you will know whether the attempt is a calculated risk or a donation.
Every market and the full archive are open from the first chart, which is the point for a challenge rehearsal: you want your rules to meet a low-volatility grind and a gap-driven week, and those are exactly the conditions that end challenge attempts. Prop firm mode itself is not a paid feature either — it is on the chart's menu from the start.
What you spend is candles: 10,000 free every week, or unlimited at $14.99 a month. A full two-phase rehearsal is a few thousand bars, so the weekly allowance covers one, and unlimited covers as many as you want — for less than a single challenge reset.
Frequently asked questions
Does CRTLAB have a prop firm mode?
Yes, and it is free. Switch it on and the session runs as an evaluation: your profit target, your maximum drawdown, one phase or two, with the target measured on closed balance and the drawdown on live equity — so an open position can breach the floor before you close it, exactly as it would in a real challenge. The link on this page opens a chart with it already running.
Can I test a trailing drawdown?
Yes. The loss limit switches between static — measured from the balance the phase began at — and trailing, measured from the highest equity the run has reached, so profit you have made becomes profit you can lose. Firms sell both and they are materially different tests; running your strategy under each before you buy an attempt takes about twenty minutes.
Can you backtest a prop firm challenge?
Yes — and it is the cheapest part of the process. Trade your strategy forward on historical data under the same rules the challenge uses: same risk per trade, same daily loss limit, same maximum drawdown. The result tells you whether the attempt is realistic before you pay for it.
What usually fails a prop firm challenge?
The drawdown rules far more often than the profit target. A strategy can be genuinely profitable over a year and still breach a maximum daily loss during a normal losing streak. That is why the losing streak and worst drawdown matter more than the average return.
How many trades should I test before attempting a challenge?
Enough that a losing streak has actually appeared in the sample — realistically a few hundred rather than twenty. A small sample almost never contains the bad run, which is precisely the thing you are trying to measure.
Does backtesting guarantee I'll pass?
No. Backtesting tells you how a strategy behaved across conditions that already happened, which is far more than most people know going in, but it is not a prediction. It converts an unknown into a measured risk rather than removing the risk.
Open a challenge and start trading it
The chart opens with prop firm mode already running on a standard two-phase evaluation — 8% target, 10% max drawdown — and every number is yours to change. No account, no card, 10,000 candles free.
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