A Testing of Semi-Strong Market Efficiency: Reverse Stock Split on Indonesia Stock Exchange Period 2007-2017

There are various reasons as to why company conducted reverse stock split. The announcement of reverse stock split could also affect the market reactions. This activity often seen as a negative signal by investors. This project focuses on test and analyze semi-strong market efficiency towards reverse stock split using three variables which are abnormal return, trading volume activity, and bid-ask spread with event window of 21 days. The samples included only 12 companies which listed on Indonesia Stock Exchange. Based on the result, Indonesia Stock Exchange has not yet achieved semi-strong market efficiency towards reverse stock split and there is significant difference on trading volume activity and bid-ask spread before and after the announcement of reverse stock split.