Overconfidence Bias
Overconfidence bias is overestimating one's knowledge, abilities, and forecast precision, leading to excessive trading and under-diversification.
Exam Tip
Overconfidence leads to excessive trading and under-diversification. Men trade more due to overconfidence. Trading costs erode 1-3% annually.
What is Overconfidence Bias?
Believing you are better at investing than you actually are.
Three Types
- Overprecision: Excessive certainty in forecasts
- Overestimation: Inflated view of abilities
- Overplacement: Believing you're better than others
Research Findings
- Overconfident investors trade 45% more
- Trading costs erode returns 1-3% annually
- Men trade more than women (lower returns)
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Related Terms
Confirmation Bias
Confirmation bias is the tendency to seek, interpret, and remember information that confirms pre-existing beliefs while ignoring contradictory evidence.
Herd Mentality
Herd mentality is following the crowd rather than independent analysis, contributing to bubbles and crashes.
Disposition Effect
The disposition effect is selling winning investments too quickly while holding losing investments too long, resulting in suboptimal returns and tax inefficiency.