The disposition effect describes a specific, well-documented, and genuinely backwards pattern in investor selling behavior: a tendency to sell winning positions too early, locking in gains, while holding losing positions too long, hoping they'll eventually recover. The name comes from a 1985 paper by researchers Hersh Shefrin and Meir Statman, titled "The Disposition to Sell Winners Too Early and Ride Losers Too Long" — and the pattern has been confirmed repeatedly in real trading data across many subsequent studies since.
This is essentially loss aversion, covered earlier in this module, applied directly to the specific moment of a sell decision. Selling a losing position means realizing — making permanent, official, undeniable — a loss that had, until that moment, only existed on paper. Loss aversion makes that specific moment feel disproportionately painful, so investors avoid it, continuing to hold and hope. Selling a winning position, by contrast, locks in a gain, which carries none of that same psychological resistance — if anything, it feels good to "take the win" before it can slip away, even when the underlying facts might actually favor continuing to hold.
Correct moves you up, wrong moves you down — reach 100 to master this lesson.