Compare
| Bias | What It Does | How It Hurts |
|---|---|---|
| Loss aversion | Losses feel 2x as painful as equivalent gains | Hold losers too long, sell winners too early |
| Overconfidence | Overestimate prediction accuracy | Overconcentrate, undertrade hedges |
| Recency bias | Weight recent events too heavily | Chase performance, panic sell after crashes |
| Anchoring | Fixate on irrelevant reference points | Won’t sell below purchase price, ignore new information |
| Herd behavior | Follow the crowd for safety | Buy at tops, sell at bottoms |
| Confirmation bias | Seek info that confirms existing beliefs | Ignore warning signs on favorite holdings |
Key point
The disposition effect (selling winners and holding losers) costs the average investor 2–4% annually in risk-adjusted returns. It’s driven by loss aversion and is the single most expensive behavioral bias.
Step through
| Debiasing Strategy | How It Works |
|---|---|
| Pre-commitment rules | Write buy/sell criteria before investing — then follow them |
| Systematic rebalancing | Calendar-based rebalancing removes emotional timing |
| Position sizing limits | Max 5% per position prevents overconfidence concentration |
| Decision journaling | Record reasoning at time of trade — review for biases |
| Cooling-off periods | Wait 24 hours before acting on market moves |
Try it
Review your recent trades. Did you sell any winners ‘to lock in gains’ while holding losers ‘until they recover’? That’s the disposition effect in action.
Check-in
The market drops 10% in a week. You feel an urge to sell everything. Which bias is driving this?
Key insight
Check-in
You've held AAPL since 2015 (+500% gain). It now represents 40% of your portfolio. What behavioral bias is MOST at risk of distorting your decision-making?
Check your understanding
Sit with the ideas.
An investor bought a stock at $80 that has fallen to $52. The company's fundamentals have deteriorated significantly and analysts have lowered earnings estimates by 40%. The investor says: 'I will sell once it gets back to $80.' What bias is driving this decision?
Why: