Why Investors Sell Winners and Hold Losers
In 1998, Terrance Odean published one of the most cited papers in behavioral finance: "Are Investors Reluctant to Realize Their Losses?" Using trading records from 10,000 accounts at a large US discount brokerage covering 1987 to 1993, Odean found that investors were 50% more likely to sell a stock that had gained value since purchase than a stock that had lost value. This pattern, known as the disposition effect, was not subtle. It was not an artifact of the data. It was a pervasive, systematic, and costly tendency that appeared across accounts of all sizes and holding periods.
The stocks that investors sold (winners) went on to outperform the stocks they kept (losers) by an average of 3.4 percentage points in the year following the sale. The investors were not just displaying a harmless quirk. They were systematically destroying portfolio value by selling their best-performing positions and retaining their worst-performing ones. They were, as Peter Lynch would say, pulling the flowers and watering the weeds.
The Psychology Behind the Effect
The disposition effect emerges from the intersection of several psychological biases.
Prospect theory and loss aversion. Kahneman and Tversky's prospect theory predicts that people become risk-averse in the domain of gains and risk-seeking in the domain of losses. When a stock shows a gain, the investor is in the domain of gains and becomes risk-averse: better to lock in the certain gain than risk losing it. When a stock shows a loss, the investor is in the domain of losses and becomes risk-seeking: better to hold and hope for a recovery than accept the certain pain of realizing the loss.
This explains the asymmetric treatment of winners and losers. The investor is not making a forward-looking analysis of each stock's prospects. They are making a backward-looking assessment of each stock's performance relative to their purchase price, and then applying different risk preferences depending on whether the stock is above or below that anchor.
Mental accounting. Richard Thaler's concept of mental accounting describes the tendency to treat money differently depending on how it is categorized. Investors create mental accounts for each stock purchase and evaluate gains and losses within each account independently. Closing a mental account at a gain feels like a success. Closing one at a loss feels like a failure. The disposition effect is partly a desire to close winning accounts (experiencing pleasure) and avoid closing losing accounts (avoiding pain).
Pride and regret. Selling a winner validates the original purchase decision. It proves the investor was right, generating a feeling of pride and competence. Selling a loser does the opposite: it confirms that the purchase was a mistake, generating regret and self-doubt. Investors seek pride and avoid regret, which leads them to sell winners and hold losers. Hersh Shefrin and Meir Statman, who first named the disposition effect in 1985, identified this pride/regret framework as the primary psychological driver.
Self-control and procrastination. Selling a loser is psychologically difficult and can always be postponed. There is always a reason to wait: the stock might recover, earnings could improve next quarter, the market might turn. This procrastination is a form of self-control failure, where the short-term desire to avoid pain overrides the long-term benefit of disciplined portfolio management.
The Evidence
The disposition effect has been documented across an extraordinary range of settings.
Odean's original 1998 study found the effect in US retail investors. Subsequent research extended the finding to professional fund managers (Frazzini, 2006), real estate investors (Genesove and Mayer, 2001), options traders (Heath, Huddart, and Lang, 1999), and even laboratory experiments where subjects traded hypothetical securities (Weber and Camerer, 1998).
The magnitude of the effect is remarkably consistent. Across studies, investors are 40-70% more likely to sell a winning position than a losing position. The effect weakens slightly with experience and financial sophistication, but it does not disappear. Even hedge fund managers and seasoned institutional investors exhibit the disposition effect, though at lower levels than retail investors.
Cultural variations exist but do not reverse the effect. Studies of investors in China (Chen et al., 2007), Finland (Grinblatt and Keloharju, 2001), Korea (Choe and Eom, 2009), and Israel (Shapira and Venezia, 2001) all found the disposition effect, though the magnitude varied. Finnish investors showed a somewhat weaker effect, possibly due to tax incentives that encouraged loss realization. Chinese investors showed a particularly strong effect, consistent with cultural research on loss sensitivity.
The Cost of the Disposition Effect
The financial cost of the disposition effect comes from two sources: the opportunity cost of selling winners too early and the direct cost of holding losers too long.
Opportunity cost of selling winners. Stocks that have appreciated often continue to appreciate due to momentum (the tendency of recent winners to keep winning over short to intermediate horizons). By selling these stocks, investors forgo the continuation of the upward trend. Odean found that the winners sold outperformed the market by a meaningful margin in the subsequent year.
More importantly, selling winners prevents the investor from benefiting from the occasional extraordinary compounding stock. The mathematics of long-term investing are driven by a small number of extreme winners. In a study of all Russell 3000 stocks from 1983 to 2006, Hendrik Bessembinder found that the entire net return of the stock market was attributable to the top 4% of stocks. The remaining 96% collectively matched Treasury bill returns. An investor who systematically sells their best-performing stocks is systematically eliminating the very positions that drive long-term portfolio returns.
Direct cost of holding losers. Losing stocks often continue to lose. The fundamental problems that caused the decline (competitive weakness, management failure, industry disruption) tend to persist. By holding these stocks, investors tie up capital in positions with below-average expected returns. The capital could be redeployed into new opportunities with better prospects, but the disposition effect prevents the reallocation.
Combined, these costs can reduce portfolio returns by 2-5 percentage points annually, depending on the investor's trading frequency and the severity of the bias. Over a 30-year investment horizon, this compounding drag is enormous. A portfolio earning 8% annually instead of 11% accumulates approximately $1,000,000 on a $100,000 initial investment, compared to approximately $2,290,000 at 11%. The disposition effect does not produce dramatic single-day losses. It produces a slow, steady erosion of wealth that is invisible in real time but catastrophic over decades.
Tax Implications
In taxable accounts, the disposition effect is particularly irrational because it reverses the optimal tax strategy. Selling winners triggers capital gains taxes, reducing after-tax returns. Holding losers defers tax benefits that could be captured through tax-loss harvesting. The optimal tax strategy is to sell losers (realizing losses that offset taxable gains) and hold winners (deferring capital gains as long as possible). The disposition effect produces the exact opposite behavior.
Odean estimated that investors in his study paid approximately $5,000 more in capital gains taxes per year than they would have paid if they had followed a rational tax management strategy. This tax drag further erodes the portfolio's after-tax returns, compounding the direct investment cost of the disposition effect.
In tax-advantaged accounts (IRAs, 401ks), the tax argument disappears, and the disposition effect should theoretically weaken. Research has found mixed evidence on this point. Some studies find a slightly weaker disposition effect in tax-advantaged accounts, while others find it persists at similar levels, suggesting that the psychological drivers (loss aversion, pride, regret) are more powerful than tax considerations in determining sell behavior.
Overcoming the Disposition Effect
Evaluate positions forward, not backward. The most effective single technique is to ask, for every position: "Would I buy this stock at today's price with today's information?" If the answer is no, the stock should be sold regardless of whether it shows a gain or a loss. This question breaks the connection between the sell decision and the purchase price, removing the backward-looking anchor that drives the disposition effect.
Set systematic rebalancing rules. A policy of rebalancing the portfolio to target weights at regular intervals (quarterly, semi-annually) forces the sale of positions that have appreciated (reducing overweight winners) and the purchase of positions that have declined (adding to underweight positions). This mechanical process removes human judgment from the sell decision and counteracts the disposition effect.
Use stop-loss and take-profit orders sparingly but deliberately. While mechanical stop-losses can be triggered by temporary volatility and are generally ill-suited for value investing, having a written policy of reviewing any position that has declined more than 25% from purchase price can create a structured reassessment that interrupts the holding-losers tendency. The review should focus on fundamentals, not price.
Track sell decisions. Maintain a record of every stock sold, the price at which it was sold, the reason for selling, and the stock's subsequent performance. Reviewing this record reveals patterns. An investor who discovers that their sold winners consistently outperform their held losers has empirical evidence of the disposition effect in their own behavior, which can motivate change.
Mental reframing. Instead of thinking about "realizing a loss," think about "freeing up capital for a better opportunity." Instead of thinking about "locking in a gain," think about "cutting off a potential multi-bagger." These reframings, while simple, can shift the emotional valence of sell decisions in a direction that counteracts the disposition effect.
The disposition effect is one of the most thoroughly documented and most costly behavioral biases in investing. It operates below the level of conscious awareness, producing decisions that feel rational in the moment but are demonstrably irrational in aggregate. Overcoming it requires not just knowledge of the bias but active, deliberate processes that substitute systematic rules for intuitive judgments. The investor who masters this substitution will, over time, hold fewer losers, retain more winners, and compound wealth at a meaningfully higher rate.
Put these principles into practice. Track fundamentals, build portfolios, and analyze stocks with AI-powered insights.
Start Free on GridOasis →