Disposition effect

The three reporters cited each other. The underlying evidence was one study, which had not been replicated.

The tendency to sell assets that have increased in value and keep assets that have decreased in value.

What it means and how it works

Key mechanisms include: (1) Prospect theory’s value function, which makes losses feel more painful than gains feel pleasurable; (2) Regret aversion, where selling a loser triggers regret over a bad decision, leading to avoidance; (3) Mental accounting, where gains and losses are treated in separate ‘accounts,’ encouraging the closure of winning positions to ‘lock in’ success while keeping losing positions open in hopes of recovery.

The disposition effect describes a pattern in which investors realize gains prematurely while postponing the realization of losses. This behavior stems from psychological factors such as the desire to feel pride from gains and to avoid the regret associated with admitting a loss. It is often linked to prospect theory, which posits that people evaluate outcomes relative to a reference point (e.g., the purchase price) and are more sensitive to losses than to equivalent gains.

Why it matters

Exhibiting the disposition effect can reduce overall investment returns because investors sell winners too early (missing further upside) and hold losers too long (incurring additional losses). This behavior can also affect market prices, contribute to momentum and reversal patterns, and undermine the efficiency of investment portfolios.

The verified research on this pattern supports the following:

• Investors are more likely to sell winning investments than losing ones.
• The disposition effect persists across different asset classes and investor experience levels.

Common misunderstandings

Misunderstanding 1: The disposition effect applies only to individual stock traders; in fact, it has been observed across various asset classes and among institutional investors.

Misunderstanding 2: It is always irrational; while it often leads to suboptimal outcomes, some investors may use it deliberately as part of a broader strategy (e.g., tax-loss harvesting).

Misunderstanding 3: It results solely from lack of information; the bias persists even when investors have full knowledge of the assets’ fundamentals.