ProEA Lab · Topic hub
Prop firm rules, decoded and computed
A prop-firm challenge is a rulebook wearing a trading account as a costume. Most failures are rule failures, not strategy failures — a daily-loss cliff clipped at the wrong hour, a trailing drawdown that moved when profit did, a consistency rule discovered on the last day.
This cluster decodes the rulebook mechanics that repeat across firms — without naming or accusing any specific firm, because rules change and we only publish what we can defend. The calculators turn each rule into arithmetic you can run before the challenge starts.
Start with the six numbers every rulebook hides. Then run your plan through the calculators until the numbers stop surprising you.
Prop-firm calculators →
consistency, profit target, drawdown recovery
Prop-Firm Challenge Toolkit →
the rulebook calculator on your chart
The rulebook
Prop Firm Consistency Rules: Your Best Day Is the Problem.
A consistency rule caps how much of your total profit one day may represent — which means your proudest green day can silently lock your payout and hand you a debt: more profit you now owe on other days before you see a cent. Here's the arithmetic nobody prints (your best day × 3.33 under a 30% cap), four worked examples, and how to size days so the rule never notices you.
Prop Firm Profit Target: A Trade Count, Not a Deadline.
An 8% target on a $100k challenge isn't 'make $8,000 this month.' At a real edge it's a specific number of trades — 64, in the worked example below — and knowing that number changes how you trade the whole evaluation. Includes the case where the honest answer is: no number exists.
The risk math underneath
Your Risk of Ruin Isn't Zero.
We computed real ruin probabilities with the same seeded engine behind our free calculator: a trader with a genuine edge, risking a 'standard' 2% per trade, has a 0.6% chance of losing half the account — and a 43% chance of touching the -10% line that fails a prop challenge. The curve doesn't climb. It explodes. Every number regenerates from one command.
Drawdown Recovery: The Math Is Brutal. The Plan Isn't.
Losing 50% means you need +100% just to get back — the asymmetry every trader learns too late. Here's the full recovery table from our public calculator, the three kinds of drawdown and how to tell which one you're in using your own journal, and the honest part: our own EA's backtest once sat 73% below its peak. We publish that number on purpose.
How Much to Risk Per Trade: The Position Sizing Math That Decides Survival
There is an exact, mathematically optimal answer to 'how much should I risk per trade.' It's called the Kelly criterion — and betting it at full strength is one of the fastest ways to blow up a real account. Here's the formula, the trap inside it, and the fraction the pros actually use.