What is the 3-5-7 rule in trading?

The direct answer

The 3-5-7 rule is a trading risk guideline commonly described as limiting risk on one trade, total open exposure, and concentration in one market or related group. The exact percentages attached to the phrase vary by source, so it is not a universal prop firm rule. Use the prop firm trading journal guide to separate personal risk rules from account requirements.

Before adopting any version, write down what each number means in your own plan. A slogan without defined inputs cannot be measured.

Treat it as a framework

One interpretation assigns the first number to per-trade risk, the second to combined open risk, and the third to a broader concentration cap. Another trader may use the phrase differently. That variation is why you should avoid presenting it as an official standard or as a rule used by every evaluation.

Your prop firm's current rulebook remains the source for maximum drawdown, daily loss, and consistency requirements. A personal allocation rule can be stricter than the firm's limits, but it does not replace them.

Define measurable fields

For each trade, record planned risk and actual size. For the account, record the maximum drawdown and any daily or consistency constraint that applies. For concentration, define which contracts or strategies count as related before the session begins.

QuantLab prop accounts store a target, maximum drawdown, drawdown already used, and a consistency limit. The dashboard calculates maximum drawdown and evaluates the consistency setting. It does not claim a built-in universal 3-5-7 setting.

Test the idea against your fills

After importing trades, identify where actual size or repeated exposure exceeded your written cap. QuantLab's behavior detectors can surface oversizing and related patterns. Replay can apply an alternate size cap or other risk limit to your own fills and show the resulting equity curve.

That test describes the historical record under a changed rule. It does not predict future performance. Keep the broker statement as the source for the executions and the firm's dashboard as the source for official evaluation status.

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Review the limits separately

Do not compress the three ideas into one pass-or-fail label. Per-trade risk answers whether one decision was too large. Combined exposure answers whether several acceptable trades became excessive together. Concentration asks whether related positions created one hidden bet.

Your journal may have enough execution data to review size after the fact, but it cannot infer every planned stop or relationship unless you record those definitions. Add the minimum notes needed to compare the actual trade with the plan. Then review the official prop account settings on their own, since a personal allocation guideline and a firm drawdown rule answer different questions.