Research On The Impact Of Major Information Disclosure Of Listed Companies On Stock Price Fluctuations

This paper studies the influence of major information disclosure of domestic retail listed companies on abnormal stock price fluctuations in 2017.90 listed companies were selected,a total of 245 events were taken as samples,and the analysis was conducted by the event research method.The abnormal rate of return was selected as the test index,which was divided into the overall sample empirical analysis and the classified sample empirical analysis.In addition,this paper analyzes the major information disclosure case of Suning acquired TTK Express and focuses on the stock price fluctuation effect of material asset transaction information disclosure.The research conclusions of this paper are as follows:(1)It is a serious phenomenon that there are both information leakage and insider trading before the disclosure of the announcement.This can cause an abnormal fluctuations in stock prices.(2)The accumulated value of the cumulative abnormal return rate of major information disclosure events of business type changing,which cause a higher possibility of stock prices' abnormal fluctuations is the highest among the five types.(3)Senior management personnel changing and suspected illegal major information disclosure on the stock price has a significant negative effect and bring adverse expectations to the market.(4)Both positive and negative major information disclosure are abnormal fluctuations in stock prices,and the range and frequency of positive fluctuations are higher.(5)The biggest gainers of abnormal returns are institutional investors and insiders.Small and medium-sized retail investors obtain small abnormal returns only and suffer more losses when bad news is released.With the conclusions above,this paper concluded as follow to reduce abnormal fluctuations in stock prices and improve the information disclosure system of listed enterprises: establish a sound regulatory system,add information disclosure system assessment;Strengthen punishment and raise the cost of breaking the law;Strengthen the internal governance of listed companies;Strengthen rational investment education and improve the knowledge of information disclosure;We will strengthen oversight of certified public accountants.