How to avoid the "sell winners, hold losers" effect

I. Core Phenomenon: Disposition Effect (Selling Winners, Holding Losers)

• Investors sell profitable assets too early and hold onto losing assets for too long, i.e., "cutting profits and letting losses run."

• Typical scenario: Holding a stock that's down 50% for years, selling it as soon as it breaks even, and then missing out on a subsequent doubling of its price.

II. Behavioral Roots: Loss Aversion and Evolutionary Psychology

• Loss Aversion (Kahneman's "Prospect Theory"): The pain humans feel from a loss is approximately twice as intense as the pleasure from an equivalent gain, leading to "unwillingness to realize paper losses and eagerness to lock in small profits."

• Evolutionary Imprint: In ancient survival environments, the instinct to "avoid certain losses" was hardwired into the brain, manifesting in financial markets as "holding onto losses and running at breakeven."

III. Institutional Exploitation: Precisely Harvesting Retail Psychology

• Big players exploit the retail investor's tendency to "sell at breakeven." When a stock price rebounds to the area where many are trapped, they create a false panic of "resistance to further gains and an impending crash," forcing retail investors to surrender their low-cost shares, thereby completing accumulation at the bottom.

IV. Data Evidence: Retail Investors Consistently Underperform the Market

• Dalbar's "Quantitative Analysis of Investor Behavior" report shows: Over the past 20 years, the S&P 500's annualized return was 9.7%, but the average investor's return was only 8.7%; in 2023, retail investors underperformed the S&P 500 by a staggering 5.5%.

• Root cause: Retail investors are driven by emotions, "panic selling during crashes and running at breakeven," perfectly missing out on compound growth.

V. Solutions: Reshaping Trading Mindset and Rules

Forget Your Cost Basis, Make Objective Decisions

◦ Turn off the "P&L display" on your trading platform, or cover the cost column with black tape.

◦ Before selling, ask yourself: "If I were starting with a cash position now, would I buy this at the current price based on its fundamentals?" If yes, hold; if no, sell decisively.

Establish Mechanized Exit Rules

◦ Set a clear plan before trading: Set stop-losses for short-term trades (sell if key moving averages/support levels are broken), and take-profit targets for long-term investments (sell in batches when reaching target price or upon seeing topping signals).

◦ Execute the rules strictly, treating yourself as an "unemotional execution machine," avoiding emotional interference during trades.

Accept Imperfection, Detach from Ego

◦ Recognize that "losses are a reasonable cost of investing"; even Warren Buffett has losing trades.

◦ Do not equate account P&L with personal intelligence/dignity; break free from the obsession with "perfect trades."

VI. Essence: A Practice Against Human Nature

The core of investing is the insight into and restraint of one's own human weaknesses, not relying on insider information or "magic indicators." Only by overcoming the instinct to "run at breakeven" can one truly profit in the market.