Walk me through the five belief perseverance biases with concrete investor examples.

Question

AcadiFi · Accepted Answer

All five are cognitive biases where prior beliefs resist updating, but the mechanism differs in each. Concrete examples:

1. Conservatism — underreacting to new information. Pietr Janssens sees Q3 earnings beat estimates by 30% but keeps his earnings model unchanged because he trusts his two-year-old base case. He anchors on the old forecast.
2. Confirmation — seeking evidence that supports existing views, ignoring contradicting data. Aviva Kostroma owns a lithium miner; she reads three bullish analyst notes and skips a detailed bearish piece on supply glut.
3. Representativeness — judging probability by similarity to a stereotype rather than base rate. Ren Mugisha treats a fast-growing SaaS IPO as 'the next Snowflake' and ignores that 80% of such IPOs underperform in year two.
4. Illusion of control — overestimating ability to influence outcomes. Solveig Dahl day-trades heavily, believing her charting skill overrides market randomness; she actually trails the index by 400 bps/yr.
5. Hindsight — remembering predictions as more accurate than they were. After a bank run, Teodora Vasilev recalls that she 'always knew' the bank was weak, even though her January notes showed no warning.

```mermaid
flowchart TB
  BP[Belief perseverance] --> C1[Conservatism]
  BP --> C2[Confirmation]
  BP --> R[Representativeness]
  BP --> I[Illusion of control]
  BP --> H[Hindsight]
```

Remedy for all: pre-commitment to rules, quantitative checklists, explicit base-rate analysis, and forecast journals to create accountability.

Walk me through the five belief perseverance biases with concrete investor examples.

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