NISM-Series-X-B: Investment Adviser (Level 2) · Behavioural Finance in Practice

Cognitive Biases in Investing: How to Identify and Correct Them

Updated 11 October 2026 · Fact-checked

Cognitive biases are systematic errors in how investors think, process information or hold beliefs. They come from mental shortcuts and faulty reasoning, not from feelings. To solve a question, read the client's behaviour, name the thinking error, and pick the fix that uses information, data and structure.

Understand Cognitive Biases in Investing

Traditional finance assumes investors are rational. Behavioural finance shows they often are not. A cognitive bias is a predictable error in thinking. It comes from how the mind handles information, memory and beliefs. It is different from an emotional bias, which comes from feelings, impulse or fear.

The usual NISM X-B split has two groups. Belief perseverance biases are about clinging to existing beliefs: conservatism, confirmation, representativeness, illusion of control and hindsight. Information processing biases are about handling data badly: anchoring and adjustment, mental accounting and framing, availability. Overconfidence is often discussed with these as well. Check how your workbook groups each bias before the exam.

Key biases in plain words:

Overconfidence: you overrate your knowledge or skill. Result: too much trading, too little diversification, underestimated risk.
Anchoring: you fix on a reference number, such as the purchase price or a past high, and adjust too little from it.
Confirmation bias: you look for facts that support your view and ignore facts that do not.
Representativeness: you judge by resemblance to a type or a recent pattern, and ignore base rates. Example: assuming a company with a few strong quarters will keep growing.
Availability: you judge likelihood by how easily an example comes to mind, such as a recent crash or a news story.

The adviser's task is to spot the bias and reduce its effect. Cognitive biases can often be corrected with better information, education and process. Emotional biases are harder to change, so the adviser usually adapts the plan around them. This is a key exam distinction.

Key formulas to remember

Cognitive vs emotional bias: Cognitive = faulty reasoning or information processing; Emotional = feeling or impulse; Cognitive biases are more correctable through information and education. Emotional biases are usually accommodated in the plan.
Belief perseverance group: Conservatism, confirmation, representativeness, illusion of control, hindsight; The common thread is holding on to a belief despite new evidence.
Information processing group: Anchoring and adjustment, mental accounting, framing, availability; The common thread is processing data in a flawed way. Overconfidence is sometimes listed with cognitive errors; follow the workbook grouping.
Bias to behaviour link: Overconfidence → excess trading; Anchoring → fixation on cost price; Confirmation → one-sided research; Availability → recent events overweighted; Use this to match a client's behaviour to the right bias.

How to solve Cognitive Biases in Investing questions

Use this method for any question that describes a client's behaviour and asks you to name the bias or the adviser's response.

1Read the scenario and underline what the client did and why they say they did it.
2Ask: is the cause a feeling (fear, regret, attachment) or a reasoning shortcut? Feeling points to emotional; reasoning points to cognitive.
3Match the behaviour to the bias: ignoring contrary evidence is confirmation; fixating on a past price is anchoring; overrating own skill is overconfidence; relying on a recent vivid event is availability; judging by a pattern or label is representativeness.
4Check the options for look-alikes. Anchoring and conservatism are close, and so are representativeness and availability.
5If the question asks for a remedy, choose the one that adds data, structure or an opposing view for cognitive biases.
6Eliminate options that name an emotional bias or give an unrelated fix, then answer.

Quickest way: Cue-word matching

When to use it: Use when time is short and the question asks you to identify the bias from a short scenario.

Spot the cue: 'my skill' means overconfidence.
'Bought at' or 'back to the price' means anchoring.
'Only reads reports that agree' means confirmation.
'Looks like a past winner' or 'good company so good stock' means representativeness.
'Recent news or crash' means availability.
If the cause is fear, regret or loss pain, it is emotional, so skip the cognitive options.

Common mistakes in Cognitive Biases in Investing

Treating confirmation bias and overconfidence as the same thing.
Both make the investor stick to a view.
Fix: Confirmation is about selecting evidence. Overconfidence is about overrating your own ability or knowledge.
Mixing up representativeness and availability.
Both involve judging likelihood from what comes to mind.
Fix: Representativeness uses resemblance to a type or pattern. Availability uses how easily or recently an example is recalled.
Calling loss aversion or regret a cognitive bias.
Students remember them as 'behavioural' and stop there.
Fix: Loss aversion and regret aversion are emotional biases. Ask whether the cause is a feeling.
Choosing 'accept and adapt the plan' as the remedy for a cognitive bias.
It is the usual answer for emotional biases.
Fix: For cognitive biases, the preferred approach is to correct through education, data and a disciplined process.
Seeing anchoring only as 'cost price' fixation.
That is the most common example.
Fix: Anchors can be any reference point: a past high, an analyst's target, an IPO price.

Worked examples

Example 1

A client bought a stock at ₹800. It now trades at ₹600 and fundamentals have weakened. He refuses to sell until it 'comes back to ₹800'. Which bias is most directly shown, and what is the adviser's best response?

Show the solution

The client fixes on ₹800, a reference point from the past.
The cause is a reasoning shortcut, not a pure feeling, so it is a cognitive bias.
Fixing on a reference value and adjusting too little is anchoring.
The remedy is to move the client's focus to the stock's current outlook and compare it with alternatives, using data.

Answer: Anchoring. The adviser should evaluate the holding on current fundamentals and expected returns, not on the purchase price.

Example 2

A client reads only research notes that support his bullish view on a sector and dismisses warnings as 'noise'. He also believes his stock picks beat most professionals. Identify the two biases.

Show the solution

Reading only supportive notes and dismissing contrary ones is confirmation bias.
Believing his picks beat most professionals, without evidence, is overrating his own skill: overconfidence.
Both come from reasoning and belief, not from feelings such as fear or regret, so both are cognitive.
A sound response is to ask for the opposing case and track his record against a benchmark.

Answer: Confirmation bias and overconfidence. Both are cognitive biases and can be reduced with balanced information and performance tracking.

Exam tips

Expect scenario questions. Name the bias from the behaviour, and watch for close pairs such as anchoring and conservatism.
Know the cognitive versus emotional split, including which can be corrected and which is accommodated.
Learn the belief perseverance and information processing grouping from your workbook and answer by its wording.
On a 2-mark caselet question a wrong answer costs twice as much, so guess only after you remove two options.

Practice questions from Behavioural Finance in Practice

Cognitive Biases in Investing in other exams

The same ground in other exams, if you are preparing for more than one or want another angle on it.

CFA Level ICognitive Errors: Information Processing Biases

Cognitive Biases in Investing: frequently asked questions

What is the difference between cognitive and emotional biases?

Cognitive biases come from faulty reasoning or poor information processing. Emotional biases come from feelings or impulses. Cognitive biases can often be reduced by education and better data. Emotional biases are usually hard to change, so advisers adapt the plan.

How do I identify a cognitive error in a client?

Look at what the client does with information. Ignoring contrary facts suggests confirmation. Fixing on a past price suggests anchoring. Overrating own skill suggests overconfidence. Then check that no strong feeling is the cause.

How does overconfidence affect an investor's portfolio?

Overconfident investors tend to trade too much, hold concentrated positions and underestimate risk. This usually raises costs and can lower returns.

Is anchoring the same as confirmation bias?

No. Anchoring is fixing on a reference point and adjusting too little. Confirmation bias is seeking and favouring evidence that supports an existing belief.