The Ex – day effect : A study about stock returns on the ex – day of dividend with the efficient market hypothesis in consideration

Question: "Does the market possess perfect information as the efficient market hypothesis says?" "Is there any significant relationship between the abnormal stock return on the ex – day and the dividend?" Purpose: The purpose of this study is to enlighten and find understanding about stock return versus dividend on the ex – day and try to figure out if abnormal returns occur on the portfolio during dividends. Methodology: The study was based in a quantitative nature and was derived with an event study and a hypothesis testing. The authors investigated the thirty most traded shares on the Stockholm stock exchange during a period of five years (2005 – 2009). They were analyzed during a total of nine days; the estimation window was set to sixty days. Theory: Leading theories in this field of study have been picked to enlighten and analysis the questions of the study. Theories used: Efficient market hypothesis, agent theory and the events of dividends. Empiricism / Results: The authors made an event study and hypothesis tested the information. From the data they could see a small abnormal return on every day except the day after the ex – day. However, they could not prove a significant relationship between the stocks return and the dividend. Conclusion / Discussion: The efficient market hypothesis was strengthened in the conclusion where all new information is reflected in the stock price because the null hypothesis was accepted in all nine cases. The authors also concluded that although they have a differentiated result compared to other studies, it could be a result of the recession. Another conclusion was that the relationship between shareholders and the management has been improved because of a better spread of information.