Research On The Impact Of Changes In The News Popularity Of Listed Companies On Stock Price Fluctuations

In recent years,with the continuous improvement of people's living standards and the increasing growth of personal wealth,people's financial awareness is gradually strengthened,leading to the increasing attractiveness of the stock market.However,compared with developed countries such as Europe and America,China's stock market has been established for a short time,and its development in mechanism construction and other aspects is not mature enough.The most important point is that investors in China's stock market are still small and medium-sized investors,namely retail investors.Most retail investors not only lack professional financial knowledge,but also spend limited time and energy on investment due to work and study.As a result,they tend to be affected by various "news" in the trading process of buying and selling stocks.Today,with the rapid development of Internet technology and the large-scale penetration of new media applications such as Douyin and Kuaishou short video platforms into People's Daily life,"news" can spread faster and more widely.As the "news" most directly related to the stock index,company news,once fermented by the media and heated up,will form a powerful information impact,which will have a certain degree of impact on investors' trading behavior,and then cause the fluctuation of stock prices.Therefore,this paper takes China's Growth Enterprise Market as the entry point,uses Python software to climb and sample the Baidu Media Index of the company as the proxy variable of the company's news heat,and uses the improved dynamic JUMP-GARCH model to study the impact of the change of news heat of listed companies on the stock price fluctuations.The results show that :(1)For most companies,the change of news popularity in the current period will significantly affect the jump intensity of stock price volatility in the current period,but it has little effect on the jump intensity of stock price volatility in the next period.At the same time,because of the difference in market sentiment and speculative atmosphere,this phenomenon is more pronounced in bear markets than in bull markets.(2)There is a certain "Surprise" effect in China's GEM market,that is,the more the news heat of a company is low and investors pay little attention to it,the stronger the influence of the change of news heat on the jump intensity of its stock price fluctuation.(3)Under the analytical framework of information asymmetry,it is found that compared with the listed companies in the inland and undeveloped regions in the central and western regions,the change of news popularity of the listed companies in the eastern coastal developed regions has less impact on the jump intensity of their stock price fluctuations.(4)Compared with large-cap stocks,small-cap stocks correspond to listed companies,the jump intensity of stock price fluctuation is strongly affected by the change of company news heat.Finally,according to the problems found in this paper and the analysis results,the paper puts forward targeted suggestions to the small and medium-sized investors,listed companies and regulators in China's stock market,in order to promote the healthy development of China's stock market to provide some help.