COLOMBO STOCK EXCHANGE
Q: How would you define behavioural biases and why is it important for investors to be aware of them?
A: Behavioural biases are classified into two categories: those arising from cognitive limitations and those driven by emotions (such as loss aversion).
In the context of investing, these biases are deviations from rational decision making caused by psychological factors – viz. emotions, cognitive shortcuts and social influences – that affect how investors perceive information and make choices.
They help explain why investors behave in ways that deviate from traditional finance theory, which assumes rational, utility maximising decision making. While rational investors are expected to optimise the risk return tradeoff, behavioural biases can lead to suboptimal decisions and less efficient investment outcomes.
Q: From your vantage point at the Colombo Stock Exchange (CSE), how significant a role do behavioural biases play in shaping investor decisions?
A: We don’t possess concrete data to determine the extent to which investors are influenced by behavioural biases as opposed to strictly following traditional finance principles. However, both rational and irrational decision making coexist, and bias driven decisions can lead to suboptimal risk return trade-offs.
Behavioural biases play a major role in shaping investor behaviour, often rivalling fundamentals such as earnings and macroeconomic indicators, particularly in the short to medium terms.
While traditional finance assumes markets are driven by corporate performance, interest rates and economic growth, investor sentiment and psychology often distort how these fundamentals are interpreted.
This is especially pronounced in markets with a strong retail investor base where biases such as overconfidence, herd behaviour, loss aversion and anchoring are more pronounced. As a result, short-term market movements are driven more by emotions and reactions to news than by fundamentals.
Over the long-term however, fundamentals tend to prevail – with earnings and broader economic conditions driving valuations. Behavioural biases do not replace fundamentals but interact with them. Fundamentals determine intrinsic value while investor behaviour drives short-term prices.
Q: Among the common biases, which do you see most frequently influencing Sri Lankan investors and how do they typically manifest in trading behaviour?
A: Several behavioural biases are observed among investors, particularly availability bias, confirmation bias, and anchoring and adjustment bias.
Availability bias arises when investors rely on recent or easily accessible information rather than conducting full fundamental analysis. Confirmation bias leads them to favour information that supports existing views while disregarding contradictory evidence, often reinforcing overconfidence and delaying rational decision making.
Anchoring and adjustment bias is also prevalent with investors fixating on reference points such as purchase price or past highs when making decisions. This can lead to reluctance to sell at a loss or the belief that a stock is ‘cheap’ simply because it is below a previous peak.
Collectively, these biases contribute to delayed loss recognition, momentum driven trading and pricing inefficiencies, highlighting the influence of investor psychology alongside fundamentals in market behaviour.
Q: To what extent do herd behaviour and sentiment driven investing amplify these biases, and how do they contribute to market overreactions or corrections?
A: These dynamics often transform individual decision errors into large-scale market phenomena. In markets such as the CSE where volatility and information asymmetry are relatively high, investors frequently look to others for cues, reinforcing biases such as availability, confirmation and anchoring.
Herd behaviour provides social validation and reduces the psychological discomfort of uncertainty. For example, if many investors are buying a particular stock, others feel reassured in doing the same, even in the absence of strong fundamentals.
Similarly, sentiment driven investing intensifies how investors interpret information. Positive sentiment strengthens confirmation bias where only favourable signals are acknowledged while negative sentiment leads to pessimism and risk aversion.
Together, these dynamics contribute to market overreactions. During periods of optimism, herd driven buying can push prices above intrinsic value while fear can drive them below fundamental levels, causing a disconnect from underlying economic realities.
However, such mispricing is corrected over time as new information emerges and sentiment stabilises. In this way, herd behaviour and sentiment coexist with behavioural biases, and also accelerate cycles of overreaction and subsequent correction.
Q: What safeguards or frameworks can investors adopt to minimise the impact of behavioural biases on investment outcomes?
A: Investors cannot eliminate behavioural biases but they can reduce their impact through structured, rule based frameworks.
A clear investment policy helps anchor decisions to long-term goals rather than short-term emotions. Disciplined diversification and periodic rebalancing reduce the tendency to chase trends or react impulsively to market movements while decision checklists ensure that choices are based on fundamentals, risks and alternatives rather than sentiment.
Maintaining an investment journal improves self-awareness by identifying recurring behavioural mistakes, and limiting excessive market monitoring helps avoid emotional overreactions to short-term volatility.
Systematic approaches such as regular investment plans enforce discipline while seeking independent advice adds objectivity and challenges personal biases.
Overall, the key safeguard is structured discipline – creating systems that support rational decision making and reduce the influence of emotion.
Q: How can data, research and analytics help investors counteract emotional or biased decision making?
A: Data, research and analytics help investors counteract emotional and biased decision making by shifting the focus from intuition to evidence based judgement.
Data provides objectivity through verified financial metrics such as earnings, cash flows and valuation ratios, reducing the influence of rumours or market movements. This mitigates biases such as availability and herd behaviour.
Research introduces structured thinking. Analyst reports, sector studies and macroeconomic analysis encourage investors to evaluate multiple dimensions of an investment, reducing confirmation bias by discouraging selective interpretation of information.
Analytics enable disciplined decision making by allowing investors to quantify outcomes rather than rely on gut feeling. For example, understanding volatility patterns or drawdowns can reduce panic during periods of market stress.
Overall, while data, research and analytics do not eliminate behavioural biases, they are a counterweight to emotion, enabling more consistent, transparent and rational investment decisions.
Q: And finallywhat differentiated advice would you offer to first time investors, experienced investors and institutional players regarding managing behavioural biases in investing?
A: From a behavioural finance perspective, how biases manifest and are managed differs across investor types. A useful starting point is to understand each behavioural bias, recognise their consequences and learn practical strategies to mitigate or overcome them.
First time investors need strong education and discipline to avoid common emotional and cognitive errors. Experienced investors, although more informed, may still be influenced by patterns such as overconfidence or confirmation bias, and require greater self-awareness and structured decision making.
And institutional players are best supported through robust governance structures, risk management systems and process driven investment frameworks that reduce reliance on individual judgment.
In summary, although all investors are affected by behavioural biases, the approach to managing them must be tailored. Successful investing depends not only on financial knowledge but also the ability to recognise and manage behavioural tendencies.
– Compiled by Prashanthi Cooray
INTERVIEWEE DETAILS
Nishantha Hewavithana
Senior Vice President – Research & Strategy
COMPANY CONTACT DETAILS
Telephone: 2356456
Email: info@cse.lk Website: www.cse.lk
