Chasing has a defining feature: the entry is worse than planned, so the stop is either far away or in the wrong place. Risk-reward collapses even if the direction is right, and the trade that works still pays badly.
The driver is anticipated-regret rather than analysis. The film of the move happening without you is more vivid than the equally likely version where you buy the high and get stopped.
The rule is mechanical: define a maximum distance beyond the trigger at which an entry is still valid, and skip everything past it. A missed move costs nothing. See fomo.
Related: fomo, anticipated-regret, chasing-losses, sending-it