股权分置改革中内幕交易和市场操纵行为研究

通过运用事件研究方法，对样本股权分置改革前后的累积超常收益率（CAR）、超常换手率（AAT）的变化趋势进行比较研究。研究发现，在股权分置改革中存在较为严重的信息泄漏从而导致内幕交易和市场操纵的行为。这种行为严重损害了证券市场的“三公”原则，削弱了资本市场效率。因此，必须强化信息披露与监管，促进股权分置改革的顺利完成。

An Empirical Study on the Insider-Trading and Market-Operating Activity in the Reform of Equity Division in China

This paper first uses the event study to analyze the trend on the AAT and CAR for the sample shares before and after the reform of division in ownership structure of shares. The result shows there is serious message leakage in the insider-trading and market-operating activity. The leakage damages seriously the principle of fairness, justice and openness and the efficiency of capital-market. Then puts forward some proposals to strengthen the disclosing and supervising and managing to carry out the reform of division in ownership structure of shares.