The rules that matter
Almost every challenge has a maximum daily loss (often 5%), a maximum total loss (often 10%, sometimes trailing) and a profit target (8–10%). Some add minimum days and a consistency rule.
The right risk per trade
With a 5% daily limit and 1% risk per trade, five losses in a row end the challenge. Risking 0.5% and stopping after two losses a day leaves you room even on bad days.
Watching the distance to the limit
Always keep an eye on the room left before the maximum loss, especially if it's trailing: after a good gain the limit rises and your margin for error shrinks.