Cutting a loss cannot be left to in-the-moment judgment.

MIND · tips · markdown source

Faced with a certain loss, people reliably gamble to avoid it. That is a stable shape in how humans weigh outcomes, not a personal weakness you can resolve by deciding to be more disciplined.

So the exit has to be mechanical, and it has to sit outside discretionary override. A stop you can talk yourself out of is not a stop.