Availability heuristic

Ask an investor why they bought a stock. Often the honest answer is a headline they remember, or a tip from a friend. That memory feels like proof. It is not.

The mind reaches for whatever example is easiest to recall. It does not reach for the example that is most correct. This shortcut is called the availability heuristic.

The cost is what gets skipped. Proper research means checking a fund's downside history, its costs, and how it behaves in a bad year. An investor who trusts the first example that comes to mind skips all of that. The workbook's own warning is blunt: this means enough research is not done, and the investor ends up missing important risks.

The workbook places this first among seven behavioural biases listed in section 1.6 (Behavioural Biases in Investment Decision Making): availability heuristic, confirmation bias, familiarity bias, herd mentality, loss aversion, overconfidence and recency bias.

Availability heuristic is about the input to a decision — which facts get noticed at all. That makes it different from the biases that come after it in the same list, which are about how an investor reacts once information is already in front of them. Loss aversion, for instance, is illustrated in the same section with a concrete number: investors weigh a Rs 5,000 loss more heavily than a Rs 5,000 gain. Availability heuristic has no such number in the workbook — it is about which examples surface in the first place, before any weighing happens.

Illustrative — the workbook names the bias but does not work an example.

Rohan opens a news app and sees a fund named as the "top performer of the year," up 62% in one year. He invests Rs 3,00,000 the same week, without checking anything else.

Had he looked, he would have found that the same fund fell 48% two years earlier, in a sector rotation. Its 5-year CAGR is a far less dramatic 14%, in line with its category average. The 62% headline was the example that came to mind. The 48% drawdown was not, because nobody was writing news stories about it at the time.

Rohan's Rs 3,00,000 is now riding the full volatility of a concentrated sector fund, sized as if it were a core holding, on the strength of one number that was simply the most available.

Chapter 1 (Investment Landscape), section 1.6, lists availability heuristic first among the behavioural biases an investor must understand as a risk in its own right, separate from market risk. Expect a question that names a scenario — an investor acting on a recent headline or a single anecdote — and asks which bias it illustrates; availability heuristic and confirmation bias are the two most commonly confused in this list.

• Availability heuristic is about which facts get noticed; confirmation bias is about how facts already in view get interpreted. A question describing an investor who only reads bullish articles after already deciding to buy is testing confirmation bias, not this.
• A recent, vivid example is not evidence of a fund's general quality. The workbook's point is that reliance on such examples means proper research is skipped.
• This is listed as an investment risk in Chapter 1, alongside credit risk and price risk — not as a footnote on psychology.