Anchoring and Adjustment Bias

Anchoring and adjustment bias is a cognitive pattern where you place too much weight on the first piece of information you encounter, then adjust insufficiently from that starting point when making subsequent decisions. The first number, price, or estimate becomes an anchor, and everything that follows is shaped by it, even when the anchor is arbitrary or irrelevant. In financial markets, this means investors and analysts consistently make decisions that are skewed toward an initial reference point rather than toward objective evidence.

Think of it like a ship that drops anchor too early: it might be in the wrong spot, but now all its movements are constrained to the radius of that chain.

Why Anchoring Happens in Financial Decision-Making

The brain uses anchors as shortcuts under uncertainty. When you are asked to estimate an unknown value, you reach for a starting point and work from there. In laboratory experiments, even clearly irrelevant numbers can anchor estimates. Researchers famously asked participants to spin a wheel with numbers from 1 to 100 and then estimate the percentage of African countries in the United Nations. The wheel's result had no bearing on the correct answer, yet it consistently shifted estimates toward the number it showed.

In financial contexts, the anchor is rarely arbitrary. It is usually a previous price, a forecast from an analyst, or the entry price you paid for an investment. Those numbers feel relevant because they are, at some point, connected to the actual asset. That connection makes the anchoring effect even stronger.

Stock Prices and 52-Week Highs Are Common Anchors

Investors frequently anchor to the 52-week high of a stock. When a stock has fallen 40% from that high, you may hesitate to sell because you are anchored to where it was, not where it is. You wait for it to "come back" rather than evaluating whether the current price reflects actual value. That hesitation costs you the ability to redeploy capital to better opportunities.

The same effect appears in reverse. When a stock is trading near its 52-week high, some investors hesitate to buy even if fundamentals justify a higher price, because the high feels like a ceiling rather than an anchor.

Analysts and Earnings Forecasts Are Affected Too

Professional analysts are not immune. Research shows that earnings forecasts cluster around prior-year figures and update too slowly when new information arrives. An analyst who forecasted 10% growth last year will often anchor next year's estimate close to that number, even when business conditions have changed substantially. This is why consensus earnings estimates frequently lag what actual results eventually show during turning points in a business cycle.

Mergers and acquisitions are another active arena for anchoring. Acquirers often anchor to a target company's recent trading price when setting a bid. A target trading at $50 that was $80 six months ago may generate a bid anchored to $80 rather than to an objective present-value calculation.

How to Counter the Bias in Your Own Decisions

Awareness helps, but it rarely eliminates the bias on its own. These practices reduce its impact.

• Establish clear criteria and valuation thresholds before you encounter any price information. Pre-commitment forces you to evaluate the asset objectively rather than relative to whatever number you see first.
• Seek out multiple independent reference points. If you have three different valuation methods pointing to different numbers, your anchor becomes a range rather than a single figure.
• Challenge your own estimate explicitly by asking what factors would justify a number significantly higher and significantly lower than your anchor. This widens the range your thinking covers.
• Work with a financial advisor or peer whose first exposure to the investment was different from yours. Their anchor will differ from yours, which reveals where your respective estimates diverge.

Sources:
https://onlinelibrary.wiley.com/doi/10.1002/9781119202400.ch11
https://online.mason.wm.edu/blog/behavioral-biases-that-can-impact-investing-decisions
https://neuroprofiler.com/en/anchoring-biases-and-financial-decisions/
https://www.meegle.com/en_us/topics/behavioral-finance/anchoring-in-financial-decisions