Overreaction Testing And Analysis Based On Behavioral Finance GEM

Since1959, economists at Roberts and Osborne’s research is p-ut forward on the basis of the efficient market hypothesis, the classical finance theory development, gradually formed a system of perfect discipline. The efficient market in China was set up late, so don’t have much research literatureabout the gem market overreaction, in most of the overreaction in China studies were focused on the main board market. This article main content is divided into three parts, one is a retrospect of the past scholars about ove-rreaction to some research, then introduces the behavior finance and overreaction phenomenon, And the overreaction to define. Two is part inspection, inspection parts using the abroad mature motherboard market-the winners from the losers usually DeBondt and Thaler group legal studied the gem market overreaction, but the lack of made some improvements, replace him with multiplication cumulative excess return method of additive cumulative excess return. Finally from the Angle of behavioral finance, analyzes the cause of excessive reaction, and puts forward Suggestions on the investment ideas.This article main research results are of two aspects:one is the growth enterprise market in China found no apparent short-term overreaction pheno menon; But in the medium and long-term significant overreaction phenomen on, the specific performance for the lack of response. Second is the lack of the growth enterprise market reaction is mainly due to the following aspects. First, psychological factors, investors generally have a conservative bias, ove rconfidence, information for myself have not willing to accept the informati on, lead to the lack of response to new information; Second, investors quali ty need to improve, in order to avoid regret and take simple imitation strate gy, leading to a "the strong stronger and the weak weaker prices"; In theen d, because our country securities market systematic risk proportion is very h igh, caused investors to focus only on macro information for a long time, a nd less attention to the company’s information, this is also tend to maintain their stock prices is one of the most important factor.