Handelsstopp på Stockholmsbörsen. Innebär handelsstoppen på Stockholmsbörsen en trygg handel och en effektiv marknad

Sammanfattning: This paper examines if trading suspensions on Nasdaq OMX Nordic - Stockholm work as a contributing factor in creating a secure trading. This has been made through an event study and examination of abnormal returns. Our results for plus tick suspensions indicate that suspensions fulfill their purpose in creating a more secure trading since the trend of abnormal return we observe prior to a suspension is disrupted. Thus, the suspension is warranted. The conclusion is that the market cannot be completely safe; as the law and practice is structured today an abnormal return is inevitable. Due to the positive significant CAAR for long periods observed prior to the suspension we suggest improvement in the operation of suspensions that could decrease the time period in which insider trading occurs. No significant results are found for minus tick suspensions which are interpreted as no insider trading takes place and security is obtained. From a perspective of market efficiency the market is not efficient in either strong or semi-strong form for plus tick suspensions, which however are not true for minus tick suspensions. Although, we can conclude that new price-sensitive information is disseminated during the suspension for both positive and negative suspensions.