A prop firm challenge is a paid evaluation used by proprietary trading firms in which a trader must hit a profit target on a simulated account without violating risk rules — typically a maximum daily loss and a maximum total drawdown — to qualify for a funded account and a profit split.
The structure inverts normal trading priorities: the loss limits are hard boundaries, breached once and the challenge is over, while the profit target merely takes longer if missed. The binding constraint is usually the daily loss limit, so passing is mostly a position-sizing problem — risk per trade must be small enough that a realistic losing streak inside one day cannot touch the limit.
Challenge fees are the firms’ revenue, and most attempts fail, so rehearsing the exact rules before paying is rational. Secuora’s replay backtester includes a prop-firm challenge simulator where you set the account size, profit target, and daily and total loss limits, then practice the evaluation against historical data.