Named after the exchange mechanism, this is the individual version: a threshold that halts activity automatically so the decision is not left to the person who is currently making bad ones.
The mechanical forms work best. A broker-side daily loss limit, a platform lockout after a set number of trades, a prop account rule, or handing the password to someone for the rest of the day. Soft versions that rely on you agreeing at the time tend to be renegotiated on the spot.
Set the levels from your data, not from ambition: the drawdown beyond which your historical execution quality collapses. See daily-loss-limit.
Related: daily-loss-limit, tilt-protocol, cool-down-period, present-bias