The Study On IPO's Premium In Shenzhen And Shanghai Stock Market

At present domestic and foreign regarding IPO(Initial Public Offerings) the research mainly concentrates above three abnormal phenomena:IPO keeps down the price (short-term returns ratio to be high),IPO long-term weak trend as well as IPO selling well market phenomenon.These three unusual situations widespread and the long-standing constituted obviously to the efficiency market serious challenge,thus receives the economist and the financial scientist's enormous attention.Regarding these questions, some scholars rest on the neoclassic economical finance theory,also some scholars carry on the explanation according to the behavior finance theory,and has made certain progress.In above three abnormal phenomena,what displays in Our country Shanghai and Shenzhen Stock market is most obvious is IPO keeps down the price the phenomenon and the IPO new stock weak trend.Since has the new stock weak trend,then very possible is because the IPO first day closing price is opposite in its reasonable price is excessively high.This article based on the new stock IPO preceding year finance information estimated that this new stock is opposite in same profession other went on the market the old shares reasonable price,then divides into the new stock IPO first day returns ratio two parts:First,because the new stock fixes a price has caused "the underpricing" the part lowly;second,because the secondary market investor responded excessively causes the new stock "the premium" the part,aimed at finally "the underpricing" and "the premium" the part conducts the empirical study separately,the real diagnosis result had indicated "the underpricing" and "the premium" the influencing factor was different,even if were the identical influencing factor,affected the direction also possibly is different.