Time and again i am reminded of this science of investment; behavioral finance. In my opinion, it is one area in Finance which has a very close connection between Theory and Reality. The concept is simple to understand and is easily observable in real world. When i think of my own investment actions in the past, it reminds me that the concepts of behavioral finance and investment biases are so very true ! Here are a few of them which most of the investors might have experienced in their life
1. Confirmation Bias : I like this one ! This bias is regarding actions of an investor post their investment decision. as an example, if you invested in stock of Sony. Then you would like the stock to do good. You will thus be 'looking' for good news about Sony. If there is any bad news, you would tend to discount it. The reason you want to see only good news is the justification of your investment decision to buy Sony. So rather than sell the stock upon bad news, you continue to hold it believing it will do good and continue to search for good news !
2. Escalation Bias : This bias too is easily observable in real world. Again if you bought a stock at say $100 and the price drops to $95. you will not sell it. nobody likes to see a loss ! most of us continue to hold onto the loss rather than book the loss. you believe someday the stock would rebound and do good. that's ok but worst would be to invest more in a losing stock to 'average down' the purchase price instead of evaluating the future prospects or financial condition of the company. Behavioral Finance texts have rightly said "Investors tend to sell their good picks too early and hold onto losers for too long" !
3. Overconfidence and Pessimism : when there is good news floating around, investors tend to be more optimistic about it. e.g. when most of the stock analysts have a positive indicator for the stock of a firm, investors give it an upward bias, flock to this stock thereby driving its price to the roof. only to realize later that they paid $50 for something which was actually worth $30. Similarly, investors tend to overreact to bad news. All this can be easily seen in everyday market movements. One day stock analysts and investors are highly pessimistic about the developments in Europe and the next day they are jumping with joy on even unconfirmed reports of possible German and French government support to the EU causing high volatility in the markets.
4. Others : Stocks perform well on Friday as opposed to Monday's similar to Holiday effect in which stocks do well on a day that precedes the holiday. Then there is January Effect in which stock returns in the month of January are better than the other months.