A股上市公司股票简称变更效应研究——基于2015年变更股票简称的A股上市公司数据统计

The Study of Stock Rename Effect in A-Share Market——based on the data of renamed companies in A share stock market during 2015

选取2015年主动变更股票简称的61家A股上市公司为研究对象,运用事件研究法分析了简称变更前后15个交易日窗口期内的股票市场效应,尤其是概念股简称变更的市场反应,结果表明,"非事件"股票简称变更公告发布会引起股票价格异常波动,在变更公告前相关股票出现显著的正平均超额收益率,公告日后反向调整;投资者对简称变更热门词汇概念股反应更强。但追踪更名后一年内公司经营状况发现,发生简称变更的公司经营状况无明显改善。

By taking the listed companies in A share stock market renamed during the year 2015 as study samples and using event study method,this paper studies the abnormal reaction of the market around 15 market day before and after the announcement of stock rename and chases the long term operation of the renamed companies.Also this paper specially focused on those renamed companies that included hot words.Study shows that stock renaming this non-event will cause relevant stock price behaves erratically.Before the announcement, relevant stock has significant excess average return.After the announcement,the market adjusts negatively.Investors have stronger reaction to those names including hot words.However, the long-term operation condition of the rename stock states that most of those companies didn＇t perform better in the following year after being renamed.