中文摘要：

通过研究2000-2004年沪深股市实施增发的86家A股上市公司在增发公告日、上市日的表现,发现公告日、上市日的平均超额收益率均为显著的负数,且上市日的负价格效应要大于公告日。老股东优先配售比例和再发行价格/前价格均对原流通股股东发生作用,而增发价格除以每股净资产和资产负债率则更多地对新流通股股东发生作用,由此印证了最初的假设：公告日股票价格波动的行为主体是原来的流通股老股东,上市日股票价格的波动主要是受新流通股股东的影响。

英文摘要：

A discovery is made after study on the performance of eighty - six listed companies with A - shares in Shanghai and Shenzhen Stock Exchanges who had made seasoned new issue from 2000 to 2004 on the Notification Date for seasoned new issue and on the date of listing, showing that the average excessive yield rates on the Notification Date for seasoned new issue and on the date of listing are apparently negative, and that negative price effect on the date of listing is more serious than that on the Date of Notification. Both the priority placement proportion for original shareholders and the ratio of new issue prices to original prices have impact on original shareholders, but both the prices for seasoned new issue divided by net asset per share and gearing ratios have impact upon new liquid shareholders, which has proved the original assumption that the stock price fluctuation on the Date of Notification is mainly influenced by the original liquid shareholders while on the date of listing by new liquid shareholders.