# Anchoring: Why the First Number You See Shapes Every Decision After
In a classic experiment, Kahneman and Tversky asked subjects to spin a wheel that landed on either 10 or 65, then estimate the percentage of African countries in the United Nations. The wheel was random — obviously unrelated to the question. Yet subjects who saw 65 gave estimates averaging 45%; those who saw 10 averaged 25%. A random number with no informational value shifted estimates by 20 percentage points.
This is anchoring: the tendency to rely disproportionately on the first piece of information encountered when making subsequent judgments. The anchor doesn't need to be relevant or accurate to exert influence.
Anchoring in financial decisions
**Purchase price anchoring.** Investors anchor to the price they paid for a stock. "I'll sell when it gets back to what I paid" is an anchoring statement — the purchase price has no bearing on the stock's current value or future prospects. The rational question is always: at the current price, is this worth holding?
**52-week high/low anchoring.** Stocks trading near their 52-week high feel "expensive" and near their low feel "cheap" — even though these reference points have no fundamental significance. A stock at its 52-week low may be cheap because it's declining toward zero; one at its high may be cheap relative to its growth prospects.
**List price anchoring in negotiation.** The first number stated in a negotiation — salary, home price, car price — anchors the entire negotiation. Sellers who set high list prices extract higher final prices even when buyers know the list price is inflated. The anchor shifts the range of "reasonable" outcomes.
**Round number anchoring.** Dow 20,000, S&P 4,000, $100/barrel oil — round numbers function as anchors. Markets often stall at round numbers because participants treat them as meaningful thresholds.
Interactive Model
Anchoring Bias Simulator
See how arbitrary first numbers distort decisions — across salary, real estate, and investing.
Employer offers first; you anchor on their number
Anchoring on the employer's offer and adjusting 10% up leaves $11,500/year on the table vs. the market rate.
Counteranchoring strategies
• Generate your own independent estimate before any external anchor is presented
• In salary negotiations: state your number first, supported by market data
• In real estate: research comparable sales before viewing listed prices
• In investing: focus on current valuation vs. fundamentals, not price vs. historical high
• When anchored: explicitly generate a counter-anchor ("what would the number be if I heard $X instead?") before adjusting
Anchoring research by Kahneman and Tversky (1974) and Galinsky and Mussweiler (2001). Salary negotiation data: candidates who state first earn significantly more. Real estate data: list price anchoring confirmed in multiple housing market studies.
Counteracting anchoring
**Generate your own anchor first.** Before seeing a price, estimate what you think something is worth based on fundamentals. Your independent estimate becomes a competing anchor that reduces the influence of the external one.
**Ask: why is this the anchor?** When you notice you're reasoning from a reference point, ask whether that reference point has any fundamental relevance. Purchase price, list price, and 52-week high/low are all arbitrary from a valuation standpoint.
**Use multiple reference points.** Anchoring is strongest when a single number dominates. Deliberately seeking multiple valuation approaches (comparable transactions, discounted cash flow, replacement cost) reduces the influence of any single anchor.
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*Related: [Loss aversion](./loss-aversion) — purchase price anchoring is reinforced by loss aversion. [Overconfidence](./overconfidence) — overconfident investors are more susceptible to anchoring on their own prior estimates.*