Merger Announcement Effects and the Amendment of Insider Trading Laws in Brazil

Abstract

Although Brazil has a long history of having insider trading laws (IT laws) in place and became the first emerging country to enforce the IT laws (Bhattacharya & Daouk, 2002), criminal sanctions and hefty monetary penalties were only made possible by the amendment of its laws against IT on October 31, 2001. We study the stock price effects of merger announcements made by 151 firms over two periods, before and after the change of IT laws. Our empirical results suggest that target firms attained positive price run-ups in pre-announcement windows before, but not after, the legal regime change. While acquiring firms had strong positive pre-announcement reactions in both legal regimes, the abnormal returns (AR) decreased in the more stringent legal regime. These results indicate that more stringent IT laws may deter IT and improve market efficiency in an emerging country.