摘要
This paper examines whether index inclusion has information content and the downward-sloping demand curve hypothesis in China. We investigate the stock price and volume effects when stocks are included in two major stock indexes, the Shanghai Stock Exchange 30 Index （SH30） and the Shenzhen Component 40 Index （SZ40）. Furthermore, we also study the performance changes after index inclusion. We find significant price and volume increases for the stocks selected by the SH30 when the index was created and announced. Thus, the original inclusion may not be an information-free event. For subsequent index inclusions, we observe significant abnormal returns but not abnormal trade volume around the announcement date. However, the stock returns quickly reversed at the post-announcement period. Moreover, the financial performance of index included firms does not improve. The evidence does not support the price pressure hypothesis in China.
