One of the most documented of all psychological errors is the tendency to be over optimistic. In general, most people do not see the need to improve the way they make decisions, as they believe that they are already making excellent decisions. The unwarranted belief that we are usually correct is a major real-life barrier to critical thinking.

People exaggerate their own abilities and this is particularly common in managing their assets. Overconfidence often results in investors being fooled by small gains in a few trades, feeling much more in control of a situation than they are. Money managers, advisors and investors are consistently overconfident in their ability to outperform the market, but fail to do so.

For example, mutual fund managers, analysts, and business executives at a conference were asked to write down (1) how much money they would have at retirement and (2) what is their net worth now. The average figures were $5 million and $2.6 million respectively. The professor who asked the question said, 'regardless of the audience, the ratio is always 2:1'. People are definitely very confident that they will at least make more money in future than now.

Overconfidence can lead to the followings:

1. Not having an investment plan
Perhaps the most common reason why investment plans fail is that the investor doesn't actually have a plan. The very first step of a rational investor is to draft a plan stating investment goals and conditions. This is to make you detached from the whole investment business and follow strictly by the book not your heart.

2. Overtrading
In Odean and Barbet's study of 78,000 investors' accounts in a large brokerage firm from 1991-1996, the most active traders scored an average return of 10% compared to the less active investors' 17.5% profits. And online traders suffer even lower returns as they tend to overtrade and thus lose money to brokerage charges.

3. Lack of diversification
Due to overconfidence, investors tend to invest heavily on a particular investment with the optimism that it will generate good returns. This lead to insufficient diversification of portfolios.

In general, overconfidence is caused by mental bias that leads investors to over-estimate their knowledge, under estimate the risk and exaggerate the control they have over a situation.

Happy investing,
Pauline Yong