A Case Study Of The Impact Of Financial Public Opinion On The Stock Price Of A-share Listed Banks

Since the emergence of the stock market in the 17 th century,it has become an important part of the financial market and even the national economic development after years of development and growth.Recently,with the vigorous development of social media in the Internet,more and more investors have begun to express opinions and express emotions on social media,forming the financial public opinion.From the perspective of behavioral finance,the discussion,analysis of stockholders and emotional venting are easy to form herd effect and diffusion reaction,which has a shock impact on stock prices.Different from previous studies,this article cuts into the micro-perspective of A-share listed banks and explores the influence of financial public opinion on the stock prices of A-share listed banks,which has certain theoretical and practical significance.The theoretical part mainly introduces text mining technology and investor sentiment index construction principle.Firstly,the financial public opinion on the stock prices of Ashare listed banks in 2019 was obtained through the Qingbo Big Data platform.Because text data cannot be directly used for data modeling,text mining technology is introduced to quantify the data.Secondly,using machine learning technology to discern investor sentiment,and through adaptive testing of the model,it was found that the support vector machine model can effectively identify the investor sentiment contained in this financial public opinion.Finally,three types of investor sentiment indexes were constructed using the above data,namely investor bullish sentiment index,investor bearish sentiment index and investor neutral sentiment index.Based on the theoretical analysis,this article conducts an empirical study on the relationship between the investor sentiment index and the stock price of A-share listed banks.Aiming at the stock prices of 34 listed banks in 2019,the A-share listed bank stock price index was constructed with the trading volume as the weight.Then,a vector autoregressive model was fitted to three types of sentiment index and stock price index.Through empirical research,it is found that changes in the investor sentiment index will have a shock effect on the stock price index,but different investor sentiment shock effects and variance interpretation effects behave differently.In the end,some effective suggestions were put forward from the perspectives of the government,investors and stock issuers.