Are Swedish Mutual Fund Managers Riding Their Losers Too Long? : An Investigation of the Disposition Effect for Professional Investors

Abstract: The fundamental assumptions in financial theory that markets are efficient and investors are fully rational are increasingly being questioned. Psychological aspects are becoming more and more important in explaining and understanding markets and investor behaviour. There is a need for investigating the behaviour of investors, not only the behaviour of prices, to accomplish healthier financial markets in the future. Not only do irrational investor biases lead to inferior returns, but on a larger scale it might have detrimental effects on markets. This study aims at exploring the disposition effect, which is the general tendency to sell winning investments too soon and holding on to losing investments too long. The focus is on Swedish mutual fund managers. It is extra important to study professional investors since they are believed to majorly set prices in the market. To do this trading data has been collected for six mutual funds. Then the proportion realized winners have been compared to the proportion realized losers, to see if there is a bias at either direction. Contrary to what was expected, the sample displayed a strong tendency to sell losers relatively more often than winners. During the time studied the market experienced a strong bull market which seems to have had an impact on the disposition effect.