Passing a prop firm challenge with an automated system

Derive risk from the rules, not from a default

A 1.5% per-trade default is sensible against a 10% maximum drawdown and reckless against a 4% daily limit. The correct sequence is to start from the firm's tightest constraint and work backwards to a per-trade risk that survives a realistic losing streak.

The arithmetic that matters is consecutive losses. At 1% risk, five losses in a row costs roughly 5% — which breaches a 5% daily limit on its own. At 0.5%, the same run costs 2.5% and leaves room. A system winning 40% of its trades produces five consecutive losses regularly, not rarely.

Cap concurrent positions harder than usual

Several positions open in the same direction is one larger bet resolved by one event, and against a daily equity limit that is the fastest available route to a breach. See correlation risk and bot opening too many trades.

On an evaluation account the sensible cap is lower than on a personal one, because the downside is not a drawdown but the loss of the fee and the attempt.

Set the bot's daily lockdown below the firm's

If the firm fails you at 5% and your bot stops at 5%, the trade that reaches the threshold will slip past it. Stopping at 3% to 3.5% leaves room for the slippage on that final trade and for any floating loss on positions still open.

This is the specific mechanism behind most surprise breaches — see prop firm account failed.

Expect it to take longer than the marketing suggests

With no time limit, a system returning a few percent a month needs several months to reach a 10% target. That is a feature rather than a problem: the alternative is raising risk, and raising risk against a daily limit is how attempts fail.

Treat the evaluation fee as the cost of a test with a known and modest probability of success, not as a purchase. Firms price them on the assumption that most attempts fail, and that assumption is correct.