Disposition Effect
The disposition effect is the empirically documented investor tendency to sell winning positions too early (to lock in gains and avoid regret) and hold losing positions too long (to avoid realising a loss), a pattern that is irrational from a tax-adjusted return perspective and typically worsens portfolio performance over time.
The disposition effect was named and formally documented by Shefrin and Statman in 1985, building on Kahneman and Tversky's prospect theory which showed that losses feel approximately twice as painful as equivalent gains feel pleasurable. This asymmetric pain response creates a systematic and predictable pattern of behaviour in retail investors: running losses and cutting profits, the opposite of the investor axiom.
In Indian equity markets, the disposition effect is well-evidenced in retail NSE trading data. Studies examining individual investor trading behaviour on NSE found that retail traders were significantly more likely to sell stocks that had risen since purchase compared to stocks that had fallen, controlling for other factors. This tendency was particularly pronounced among less experienced traders and in small and mid-cap stocks where liquidity constraints were lower.
The financial cost of the disposition effect operates on multiple levels. First, by selling winners prematurely, investors capture only a fraction of multi-year compounding in quality businesses — a stock that grows from ₹100 to ₹150 and is sold (a 50% gain) may reach ₹500 over the next five years, meaning the investor missed 230% additional gain. Second, holding losers means continued exposure to deteriorating businesses — a stock falling from ₹100 to ₹60 that is held 'for recovery' may continue to ₹20 if the underlying business is structurally impaired. Third, the tax dimension in India reinforces the irrationality: selling winners held beyond one year triggers LTCG at 12.5%, while selling early (before one year) incurs STCG at 20%. Holding losers beyond one year to 'avoid loss' means eventually realising an LTCG loss (usable only against LTCG or STCG) rather than the more flexible STCG loss.
The recommended corrective is a systematic process-based approach to portfolio review: evaluating each position based on current fundamental outlook rather than relative to cost price. The question 'would I buy this stock today at this price?' is a powerful decision filter. If the answer is no, holding it purely to avoid booking a loss is irrational. Professional fund managers use formal review frameworks and investment committee oversight partly to counteract disposition-type biases at the fund level.