Abstract: Stock price synchronization is an important index to measure the information efficiency of capital marketThe influence mechanism of stock price synchronization has always been a hot issue in financial researchThrough text analysis and machine learning, this paper measures the irrational noise in the comments posted by Chinese investors in the Oriental Fortune Forum, and tests the relationship between the noise in the stock network platform and the stock price synchronizationThe research finds that, first, the noise in the stock network platform will induce irrational investment decisions, thus reducing the synchronicity of stock price changesThe higher the proportion of noise comments, the lower the synchronicity of share price of listed companies, and there is an inverted Ushaped nonlinear relationship between the twoSecond, the increase in company stock news and announcements, the increase in analyst attention, and the improvement of external audit quality can all reduce the impact of noise in the stock network platform on stock price synchronizationThis paper focuses on the impact of the noise in network new media on stock price synchronizationThe conclusions are of practical significance for the regulatory authorities to strengthen the network information monitoring and for the listed companies to further improve the information disclosure channels

Key words: stock price synchronization, irrational noise, text analysis, information disclosure

摘要： 股价同步性是衡量资本市场信息效率的重要指标。股价同步性的影响机制一直以来都是金融研究的热点问题。本文使用文本分析的方法，通过机器学习度量了东方财富股吧中股民发帖评论中的非理性噪音，检验了股票网络平台中的噪音与股价同步性之间的关系。研究发现：第一，股票网络平台中的噪音会促使投资者做出非理性的投资决策，进而降低股价变动的同步性。噪音评论占全部评论的比例越高，上市公司的股价同步性越低，而且两者之间呈现倒U型的非线性关系。第二，公司个股新闻与公告数量的增加、分析师关注度的提高与外部审计质量的提升，均可以减弱股票网络平台中的噪音对股价同步性的影响。本文关注网络新媒体中的噪音对股价同步性的影响，研究结论对于监管部门加强网络信息监测以及上市公司进一步完善信息披露渠道具有现实意义。

关键词: 股价同步性, 非理性噪音, 文本分析, 信息披露