“Mimickers” Of Corporate Insiders And Testing For Market Efficiency: The Case Of Greece

Abstract

Most prior research shows that corporate insiders can systematically earn abnormal returns by trading their own securities, but the majority of studies suggest that outsiders cannot earn abnormal returns by “mimicking” the trades of insiders after the latter report their trades. Our study is the first to investigate the case of “mimicking” in the Greek stock exchange, and the findings indicate that indeed, outsiders cannot earn significant abnormal returns by mimicking insiders’ trades, a result that is consistent with the concept of a semi-strong form of market efficiency.