A well-documented pattern in behavioral finance, and a specific one worth recognizing in your own trading.
The disposition effect is the well-documented tendency to sell winning positions too early to lock in a gain, while holding losing positions too long hoping they'll recover, driven by loss aversion rather than a rational read of each position's actual outlook.
Selling a winner converts an unrealized gain into a confirmed one, which feels rewarding in the moment. Selling a loser converts an unrealized loss into a confirmed one, which feels like admitting a mistake. Since losses are felt more intensely than equivalent gains, that asymmetry pushes traders toward locking in wins early and avoiding the discomfort of a realized loss for as long as possible, regardless of what each position's actual fundamentals or setup calls for.
PnL App logs the decisions behind every trade, so a bias like this one shows up as a real, measurable pattern instead of a feeling you can rationalize away.