Our main findings can be summarized as follows : the shock of information is the key cause for institution investors to buy and sell ; neither the two pure strategy equilibriums is risk - dominant equilibrium ; the games among the institution investors are dynamic repeated process with the shock of information 结果表明,信息冲击是导致机构投资者做出买卖决策的关键原因;机构投资者的合作均衡和背离均衡均不是风险占优均衡;在信息冲击下,机构博弈是动态的重复博弈过程。