Our thesis researches the Halloween effects in the Swedish stock market from a sector perspective. The notion Halloween effect refers to higher returns during the period November until April than the period May until October. The anomaly has been confirmed by previous researchers in Sweden among other countries. There has not been any definite explanation for this anomaly. The majority of explanations base on the assumption that the anomaly is a market wide and induced by changes in investment behavior. However, previous research has shown that the Halloween effect could be limited to certain sectors which experience significantly higher returns during winter months than the summer months. The sectors that exhibited the high Halloween effect tend to be heavy industry sectors while consumer oriented sectors tend to outperform during summer periods. In our study we research the Swedish sectors to test whether the findings of previous researches are true for other market as well. Our result indicates that the Halloween effect is present in a few sectors and not market wide. The findings thus support previous research that the Halloween effect is sector specific. The sectors that exhibited the highest Halloween effect were sectors in heavy industry.

This study has applied a geographical perspective with the ambition of evaluating the presence of the Sell in May effect, January effect and monthly anomalies in the Nordic stock markets. In extension the study examines the relationship between corporate size and the returns of calendar anomalies. The study has conducted statistical tests based on Newey-West regressions as well as a Generalized Auto-Regressive Conditional Heteroscedasticity model. The findings suggest that the Sell in May and January are present in the Nordic region and partially abide by theory and results of previous research. The findings suggest that the Sell in May and January effect are independent, however, tendencies when the January effect has a considerable influence on the Sell in May effect are also evident. Additionally, the “April Effect” is an unexpected outlier with positive excess returns that was identified through this study.