An Emnirical Studv On Insider Trading In Chinese Stock Market Based On Fixed PIN Model

Insider trading has been very popular in recent years,the problem is endless.Insider trading has undermined the order of financial markets and capital markets,seriously affecting the interests of the majority of investors.China Securities Regulatory Commission is stepping up efforts to combat insider information transactions,related party transactions and market manipulation and other illegal acts.China's capital market is not perfect,laws and regulations and other supporting measures can not keep up with the speed of financial innovation.All kinds of insider trading violations using a variety of clever means to cover up the past,the SFC on how to monitor,how to effectively monitor these illegal acts,want to break their brains.In recent years,large data systems have been applied to the insider trading regulation.These means can provide more effective than the traditional means of regulation,can be excavated can not directly observe the insider trading behavior.But these measures are not enough.Research insider trading behavior is still very important.Previous theoretical studies tend to focus on qualitative aspects,the use of PIN model(insider trading probability model)to study also increased in recent years,the relevant theory also need to be improved.This paper examines the relevant literature review of insider trading research and finds that the PIN model is still flawed in the study of insider trading cases in China.So the author proposed a modified PIN model.This paper chooses 37 sample insider trading cases for the SFC as of June 30,2015.Found that the traditional PIN model,insider trading period although the PIN value has increased,but not statistically significant,the traditional PIN model of insider trading recognition ineffective.This may be because some insider cases of insider trading time is too short,the traditional PIN model can not determine the identification.In this paper,the modified PIN model is used to test the insider trading behavior.Compared with the traditional PIN model,the modified PIN model uses the continuous change time period to measure the change of the PIN index during the insider trading period.This method can be used to observe the short-Insider information about the degree of asymmetry.The results show that the PIN value of the insider trading period has peaked,and the revised PIN index has declined after the announcement date,which explains the degree of asymmetry of information during insider trading.The modified PIN model is statistically significant compared to the traditional PIN model.It is proved that the modified PIN model is more effective by comparing the traditional PIN model with the modified PIN model,which is an improvement and supplement to the study of insider trading.