Heterogeneous,Institutional,Investors’,Stock,Investment,Return,Effect,Research Institutional名词

　　Abstract: This paper uses the event study method and takes the institutional investors holding A-share listed companies from 2009 to 2010 as the research sample, According to the investment period, institutional investors are divided into long-term and short-term institutions investors. Studies have found that long-term institutional investors holding shares of stock can get higher excess rate than short-term institutional investors holding stock over the same period, and with the passage of time, long-term institutional investors holding the stock may still be able to gain significant excess payment effects, short-term institutional investors holding the stock would not be allowed.
　　Key words: The long-term institutional investors; The short-term institutional investors; Shareholding changes; Abnormal returns.
　　1 Introduction
　　As institutional investors continue to grow and develop, the study of institutional investor has become a hot topic in academic circles, but many of the studies, there is an outstanding problem which ignores the heterogeneity among institutional investors. In reality, different types of institutional investors in funding sources, investment objectives, performance evaluation, legal, and supervision are all different, institutional investors need to consider the impact of these factors in their investment policies, so that different types of institutional investors"" investment philosophy and investment behavior characteristics are very different. Compared to the individual investors, Institutional investors because of their own characteristics, they have more access to information channels, as well as more information mining capacity and processing power (Hand 1990; Jiambalvo, Rajgopal and Venkataehalam 2002), the institutional investors have strong information superiority to acquire non-public "soft information"(Brous and Kini 1994) ,so that they can to be able to gain great earnings from investing in the stock market.
　　Depending on the institutional investors’ holding period, institutional investors will be classified as long-term and short-term institutional investors. We finds that long-term institutional investors holding shares of stocks can obtain higher excess rate than short-term institutional investors holding over the same period, and long-term institutional investors holding stocks have the over-compensation effect for a long time, but short-term institutional investors holding shares do not have this effect.