Insider Trading, News Releases, and Ownership Concentration
研究英国内幕交易的市场反应，发现英国较快的交易报告制度导致更大异常收益，且董事和外部股东持股影响该收益，并购和CEO更换新闻前的交易信息含量较低。
ABSTRACT This paper investigates the market's reaction to U.K. insider transactions and analyzes whether the reaction depends on the firm's ownership. We present three major findings. First, differences in regulation between the U.K. and United States, in particular the speedier reporting of trades in the U.K., may explain the observed larger abnormal returns in the U.K. Second, ownership by directors and outside shareholders has an impact on the abnormal returns. Third, it is important to adjust for news released before directors' trades. In particular, trades preceded by news on mergers and acquisitions and CEO replacements contain significantly less information.