BEHAVIORAL FINANCE & INVESTOR PSYCHOLOGY
Plain English
Your biggest enemy in investing is often yourself. Behavioral finance studies why investors make irrational decisions — buying high due to FOMO, selling low in panic, holding losers too long, and cutting winners too short. Knowing these biases is the first step to overcoming them.
Going deeper
Behavioral finance identifies systematic cognitive biases that lead to poor investment decisions. Key biases: Loss Aversion (losses feel 2x worse than equivalent gains feel good — causes holding losers too long); Recency Bias (overweighting recent events — buying after rallies, selling after drops); Confirmation Bias (seeking information that confirms existing beliefs while ignoring contradictory data); Herd Mentality (following the crowd — buying tops, selling bottoms); Overconfidence Bias (overestimating your ability to pick stocks or time the market); Anchoring (fixating on arbitrary reference prices like purchase price or 52-week high/low); Disposition Effect (selling winners early to lock in gains while holding losers hoping for recovery).
Examples
Loss Aversion in Action
You bought a stock at $100. It drops to $60. Despite negative fundamentals, you refuse to sell because 'it's not a loss until I sell.' Meanwhile, you quickly sell a winner up 15% to 'lock in gains.' This is loss aversion + the disposition effect destroying your portfolio.
FOMO at the Top
A stock has tripled in 6 months and is all over the news. You feel like you're missing out. You buy at the top, just as early investors are selling. This recency bias (assuming recent performance continues) and herd behavior are among the most expensive mistakes investors make.