The effectiveness of insider trading disclosure policies: US and EU comparison

Purpose - The purpose of this study is to examine the effectiveness of financial market rules in protecting minorities. Design/methodology/approach - The study compares two alternative disclosure rules on insider trading, namely, the market abuse directive (Directive 2004/72/EC), inspired from the United State (US) insider trading regulation enacted by the Sarbanes–Oxley act and the transparency directive enacted by the European (Directive 2004/109/EC) dealing with the crossing of the shareholding threshold. To investigate which one is more effective in signaling reserved information, and thus in reducing information asymmetry, the authors run an event study on the French context, where both regulations are adopted. The data were hand collected from the French stock exchange securities commissions during the two years following the implementation of the two regulations in 2004. The final sample consists of 363 insiders trading and 35 crossing shareholding thresholds for 10 top French firms during the period 2006-2007. Findings - The results show that the French market reacts significantly to insider trading, but poorly to the crossing shareholding thresholds. Abnormal returns are greater after insider purchases than after crossing up thresholds. These findings support the superiority of the insider disclosure regulation, as it has better information content and provides better protection to minorities. Research limitations/implications - The study contributes to the corporate governance literature by comparing two disclosure-trading policies. The authors conclude that regulation of disclosure of insider trading along the lines of US disclosure rules is more informative to the market and thus more relevant and important than disclosure of cross-threshold trades. Practical implications - The study contributes to the corporate governance literature by comparing two disclosure-trading policies. The authors conclude that regulation of disclosure of insider trading along the lines of US disclosure rules is more informative to the market and thus more relevant and important than disclosure of cross-threshold trades. This finding can be helpful for the securities lawmakers and regulators in the process of insider trading law enforcement. Originality/value - Previous researchers approached the question of insider trading focusing on the identity of insiders. In the research, the authors address the question from another perspective, namely, the crossing of thresholds. Another methodological contribution of the study is the use of a market model that incorporates GARCH (generalized autoregressive conditional heteroskedastic) effect and time-varying systematic risk parameter (β), which is recommended to tackle the classical event study problem of detecting the exact timing of the event.