Research On The Influence Of Network Public Opinion On The Stock Price Fluctuation Of Yiling Pharmaceutical

With the rapid development and popularization of mobile Internet,social media such as Weibo and forums have penetrated into all aspects of people ’s lives at an unprecedented rate.In the securities market,the channels for investors to obtain information are mostly based on major Internet platforms.Various kinds of good and bad information,real information or false information in social media also emerge in endlessly.These multi-source information are mixed into online public opinion,which affects investors ’ rational judgment on the stock market and has a certain impact on the stock price fluctuation of listed companies.In this context,taking into account that during the epidemic period from 2020 to2022,Yiling Pharmaceutical and its products Lianhua Qingwen have attracted much attention,often causing hot public opinion and large stock price fluctuations.Therefore,this paper selects Yiling Pharmaceutical as a case study to study the impact of online public opinion on its stock price fluctuations.The case introduction part first introduces the basic situation of Yiling Pharmaceutical,and sorts out the specific network public opinion events of Yiling Pharmaceutical from 2020 to 2022 according to the time point.Secondly,through crawler technology,the stock review of Oriental Fortune Stock Bar was obtained,and the emotional tendency of the stock review text was analyzed accordingly.Finally,starting from the three communication channels of public opinion,namely investor attention,investor sentiment and investor cognition,and drawing on the practices of previous scholars,the relevant network public opinion indicators-public opinion heat index,sentiment index and divergence index are constructed respectively.The purpose is to study its impact on stock price volatility from different channels of network public opinion.In the case analysis part,this paper first discusses the correlation between network public opinion and stock price fluctuation of Yiling Pharmaceutical through chart analysis and correlation coefficient.Secondly,TVP-VAR model is used to analyze the time-varying characteristics of network public opinion index affecting stock price fluctuation,including the impulse response of three kinds of public opinion index to stock price fluctuation based on different lead time and different time points.Finally,the network public opinion index is incorporated into the heterogeneous autoregressive(HAR-RV)model based on high-frequency data to study whether the network public opinion information can improve the prediction accuracy of stock price volatility.Through the above analysis,this paper draws the following conclusions : First,the network public opinion index of Yiling Pharmaceutical has a correlation with stock price volatility.Among them,the network public opinion heat index has a significant positive correlation with the company ’s stock price volatility;secondly,the impact of network public opinion index on stock price volatility under different lead times has time-varying characteristics.Third,the network public opinion index has different responses to stock price fluctuations at different time points;fourth,the inclusion of network public opinion index can improve the prediction accuracy of stock price volatility.Based on this,this paper gives relevant suggestions from the perspectives of regulatory authorities,listed companies and investors.