Abstract

The study aims at testing the efficiency of Amman stock exchange at the semi- strong level and examining the effect of announcement of stock offering for placement by the existing companies on stock prices of Amman stock exchange (ASE). The researchers followed the event study methodology. The importance of this research is to highlight the motives that make the managements of the companies registered at ASE tend more to financing through stock issuance than to debt financing. Results showed that the abnormal Returns after the event don't have statistical significance , its graph shows that Amman Stock Exchange is inefficient at the Semi- Strong level and these a leak in the information pertaining to stock offering before the approval of Commission on the offering at the Semi #x2013; Strong Level. However these results are consistent with evidence provided in (Siswesik 2002, Costello 2004, and Malhotra 2010.) The study presented a number of recommendations that may be helpful in improving the efficiency of the ASE, which in turn increases its role in the Jordanian economy as whole.