Behavioural Finance

Behavioural finance looks at investor behaviour to explain 

• why individuals make the decisions that they do, 
• whether these decisions are rational or irrational.

It is based on the premise that individuals, due to the presence of behavioural biases:

• do not always make "efficient" investment decisions, or 
• do they always act "rationally" 

These behavioural biases include:

• Loss Aversion
• Herding
• Overconfidence
• Information Cascades
• Representativeness
• Mental Accounting
• Conservatism
• Narrow Framing

Whether investor behaviour can explain market anomalies is a subject open to debate.

• If investors must be rational for the market to be efficient, then markets cannot be efficient.
• If markets are defined as being efficient, investors cannot earn superior risk-adjusted profits consistently.