Confirmation Bias

After a sharp market decline that almost no forecaster called in advance, client Desmond Achterberg tells his IAR that the downturn was obvious all along and that they should have moved to cash beforehand. The bias he is displaying is:

1. A.Hindsight bias, because knowing the outcome has made a genuinely unforeseeable event feel as though it had been predictable.Correct. Memory of prior beliefs shifts toward the realized outcome, inflating confidence in his own foresight and encouraging market timing.
2. B.Regret aversion, because he is reluctant to make a decision he might later regret.Incorrect. Regret aversion produces hesitation about FUTURE decisions. He is making a confident claim about the past.
3. C.Confirmation bias, because he seeks out information that supports a view he already holds.Incorrect. He is not filtering evidence for an existing thesis; he is misremembering how predictable a past event was.
4. D.Loss aversion, because the pain of the decline exceeds the pleasure of an equivalent gain.Incorrect. Loss aversion describes asymmetric feelings about outcomes; it does not involve a claim that the outcome was foreseeable.

Why: This is hindsight bias, the tendency to believe after the fact that an outcome was predictable before it occurred. Once people know how events turned out, their memory of what they previously believed shifts toward the realized outcome, so genuinely uncertain events feel as though they were foreseeable. It is damaging because it makes investors overestimate their own forecasting ability, which in turn encourages market timing and abandonment of a documented long-term plan. The practical defence is contemporaneous documentation: a written investment policy statement and dated meeting notes let the adviser show what was actually known and decided at the time.

After three strong years for technology shares, Ottoline Quist tells her adviser she wants 80% of her portfolio in that one sector because it is "clearly what works now." Two years earlier, following a market slump, she had insisted on holding nothing but cash. The bias driving BOTH requests is best described as:

1. A.Mental accounting, the treating of money differently depending on which mental pot it occupiesShe is not segregating funds by purpose; she is extrapolating recent performance.
2. B.Confirmation bias, the seeking out of only that evidence which supports a conclusion already heldHer conclusion reverses when the data reverse, which is the opposite of clinging to a prior belief.
3. C.Recency bias, the over-weighting of the latest results and their projection into the futureCorrect. Her conviction tracks whatever the market has just done.
4. D.Anchoring, the fixing of judgment on an irrelevant reference number such as an original purchase priceNo specific number is anchoring her judgment; it is the direction of recent returns.

Why: Recency bias is the tendency to give the most recent results disproportionate weight and to extrapolate them into the future. It explains both requests: after a slump the recent past looked dangerous, so she wanted only cash, and after a rally the recent past looks safe, so she wants concentration. The practical consequence is buying high and selling low, which is why a written policy allocation and disciplined rebalancing are the standard antidotes.

Convinced that a small biotechnology holding will double, Xiomara Petrov-Ellsworth reads every bullish analyst note on the company, dismisses two downgrades as "written by people who do not understand the science," and declines to review the competing trial data her adviser sends. This behavior best illustrates:

1. A.Loss aversionLoss aversion is the asymmetric pain of losses; nothing here turns on realizing a loss.
2. B.Mental accountingMental accounting separates money into distinct buckets, which is not what she is doing.
3. C.Anchoring on the purchase priceShe is filtering new evidence, not fixating on a specific reference price.
4. D.Confirmation biasCorrect. Seeking supportive analysis and dismissing contrary evidence is textbook confirmation bias.

Why: Confirmation bias is the tendency to seek out and give weight to information that supports a conclusion already reached, while discounting or avoiding evidence that contradicts it. It leaves a client unable to update a thesis as facts change and is a common driver of concentrated, deteriorating positions. An adviser addresses it by deliberately presenting the disconfirming case and by agreeing on objective sell criteria in advance.

Client Basil Oyelowo insists that Farrier Optics is really worth $82 because that was its price on the day he first researched it three years ago, even though the company has since lost its two largest customers. He also reads only the bullish analyst notes his adviser forwards and dismisses the bearish ones as poorly researched. The two behavioral biases most clearly on display are:

1. A.Herding and regret aversion.Incorrect. Herding means following the crowd, and he is doing the opposite by ignoring negative consensus research.
2. B.Anchoring and confirmation bias.Correct. Fixing on the original $82 price is anchoring, and filtering research to keep only supportive views is confirmation bias.
3. C.Overconfidence and mental accounting.Incorrect. Nothing suggests he overrates his own skill, and mental accounting means treating separate pots of money by different rules.
4. D.Availability bias and hindsight bias.Incorrect. Availability bias relies on vivid recent memories, and hindsight bias is believing past events were predictable. Neither is described.

Why: Anchoring is the tendency to fix on an initial reference number, here the $82 price he first saw, and to judge all later information against it rather than against current fundamentals. Confirmation bias is the tendency to seek out and credit information that supports a conclusion already held while discounting information that contradicts it, which is exactly what he does with the analyst notes. Recognizing these patterns lets an adviser reframe the discussion around current facts rather than argue with the client conclusion directly.