Behavioural Finance: Biases That Move Markets
After ESG & Sustainable Finance Explained, the next question is why markets do not always behave rationally even when information is available. Behavioural finance bridges psychology and economics, explaining why markets are not always rational and how cognitive biases affect investor decision-making. In interviews, it gives you a practical lens to explain why investor psychology - not just fundamentals - can drive buying at peaks, selling at bottoms, and poor portfolio decisions.
- Behavioral finance bridges psychology and economics, explaining why markets are not always rational and how cognitive biases affect investor decision-making.
- Anchoring is over-reliance on the first piece of information encountered, such as investors anchoring to 52-week high.
- Herding is following the crowd regardless of own analysis, such as retail SIP inflows accelerate at market peaks and redemptions at bottoms.
- Loss Aversion is pain of losses 2x the pleasure of equivalent gains, linked to Prospect Theory.
- Overconfidence shows up when retail F&O traders continue trading even when 89% lose money.
- Disposition Effect means selling winners too early, holding losers too long, such as booking profits on TCS at 20% gain while holding Yes Bank to zero.
- Sunk Cost Fallacy means continuing investment because of past costs, not future value, such as averaging down on DHFL or Jet Airways.
Why Behavioural Finance Matters
Behavioral finance bridges psychology and economics, explaining why markets are not always rational and how cognitive biases affect investor decision-making. Kahneman & Tversky's Prospect Theory showed that investors are not rational maximisers.
Understanding these biases helps you avoid them - and helps you understand market inefficiencies. Behavioral finance explains market inefficiencies - anchoring, herding, and loss aversion create persistent and exploitable mispricings.
Behavioral finance bridges psychology and economics, explaining why markets are not always rational and how cognitive biases affect investor decision-making.
How Biases Move Investor Decisions
Anchoring is over-reliance on the first piece of information encountered. In the Indian market example, investors anchoring to 52-week high may refuse to sell even as fundamentals deteriorate.
Herding is following the crowd regardless of own analysis. Retail SIP inflows accelerate at market peaks (FY22 all-time highs); redemptions at bottoms (Mar 2020).
Loss Aversion is pain of losses 2x the pleasure of equivalent gains (Prospect Theory). This is visible in holding loss-making Paytm / Zomato for years hoping to 'break-even' vs cutting losses.
Portfolio Mistakes Created by Bias
Overconfidence is overestimating one's predictive ability. Retail F&O traders: 89% lose money (SEBI study) yet continue trading.
The Disposition Effect means selling winners too early, holding losers too long. A clear example is booking profits on TCS at 20% gain while holding Yes Bank to zero.
Mental Accounting means treating money differently based on its source/category. It appears when investors treat Diwali bonus as 'fun money' for speculation vs treating salary savings conservatively.
Information Biases and Market Expectations
Confirmation Bias is seeking information that confirms existing beliefs. An investor may read only bullish analyst reports on a stock already owned.
Recency Bias is over-weighting recent events in predictions. The Indian market example is expecting Nifty to fall in 2021 because it fell in 2020; missing the bull market.
Availability Heuristic means overweighting memorable events in probability judgments. It appears as over-weighting crash risk after 2020 COVID sell-off; being too conservative.
FOMO, Representativeness and Sunk Costs
FOMO is Fear of Missing Out - buying at peaks driven by social proof. Crypto, NFT, and SME IPO frenzy in 2021-2022 is the Indian market example.
Representativeness is judging probability based on superficial similarity. It shows up when an investor assumes a company in a hot sector is worth investing in without financial analysis.
Sunk Cost Fallacy means continuing investment because of past costs, not future value. A common Indian market example is averaging down on a fundamentally broken story (DHFL, Jet Airways).
Structuring a Behavioural Finance Interview Answer
"Tell me about a behavioral bias that affects markets."
The strongest answer does not only define the bias. It links the bias to a concrete Indian market example such as Paytm, Zomato, TCS, Yes Bank, DHFL, or Jet Airways.
The most frequent error is treating markets as fully rational and reducing every price movement to fundamentals. That costs points because behavioral finance specifically explains why markets are not always rational and how cognitive biases affect investor decision-making.
Conclusion
Behavioural finance matters because it explains how anchoring, herding, loss aversion, overconfidence, and sunk costs can shape real investment behaviour. For interviews, the key is to define the bias, connect it to an Indian market example, and show how investor psychology can create market inefficiencies.