| With the continuous progress of the reform of the capital market,Chinese stock market is gradually getting healthier,and its function of investment and financing is more apparent.The multi-level capital market system is constantly improved.However,Chinese stock price volatility is always too high.Excessive stock price volatility will bring risk to the development of capital market and investors’wealth.Therefore,the academic community has been paying close attention to how to get the stock market out of the current situation of excessive stock price volatility and carrying out a series of studies about influencing factors of stock price volatility.This can provide direction of supervision for supervisors,can provide direction of stabilizing stock price for companies and can provide methods of evaluating enterprise value for investors.Customers are an important part of enterprises’supply chain and are the main sources of their income.Customers can affect the business situation and decision-making of enterprises and affect their stock price.China Securities Regulatory Commission has also fully realized the important position of customers in the development of enterprises and gradually put forward more perfect requirements for corporate customer information disclosure,from requiring companies to disclose the percentage of sales revenue of the top five customers,to encouraging companies to voluntarily disclose specific information about the top five customers,to requiring disclosure of information about the largest customer that account for more than 50 percent of sales revenue.Increasingly strict and detailed information disclosure requirements reflects that the existence of major customers is indeed an important factor affecting the stock price of enterprises,which should arouse the concern of enterprises and investors.So this paper explores the influence of major customers on stock price volatility and studies the influence of customer concentration on corporate stock price volatility.This paper use empirical analysis methods,choosing 2013-2020 as the research period and A-share listed companies as the sample companies.Customer concentration is measured by the proportion of the sales revenue of the top five customers in the total sales revenue,and the stock price volatility is measured by the standard deviation of daily logarithmic rate of return of stock price within a year.This paper firstly studies the influence of customer concentration on stock price volatility by regression,which is the basic research.Then this paper studies the moderating effects of institutional investors’ shareholding and the nature of corporate equity and also carries out heterogeneity analysis.Finally this paper has the following conclusions:(1)High customer concentration will increase the degree of stock price volatility.That is the higher the customer concentration,the greater the stock price volatility of an enterprise.And under a series of robustness tests such as instrumental variable method,replacing explanatory variables and adjusting test samples,the results are still valid.(2)In terms of moderating effect,institutional investors can play the role of supervision and governance to reduce the aggravating effect of high customer concentration on corporate stock price volatility.When the ownership nature of enterprises is state-owned,the aggravating effect of high customer concentration on stock price volatility will be alleviated to a certain extent.(3)The regression results of heterogeneity analysis show that the influence of customer concentration on stock price volatility is significantly different with different levels of firm specific investment,market value,internal governance efficiency and regional location:the aggravating effect of high customer concentration on corporate stock price volatility is only significant in enterprises with high specific investment level,with low market value,with low internal governance efficiency and in developed eastern regions.The research results of this paper show that the higher the customer concentration,the greater the stock price volatility of an enterprise.Therefore,enterprises,regulatory authorities and investors should pay more attention to the adverse impact of high customer concentration on corporate stock price.Companies should strengthen customer relationship management and avoid over-dependence on major customers.The regulatory authorities should pay close attention to the changes in the relationship between corporate customers and require enterprises to disclose more specific customer information.Investors should establish the awareness of risk prevention and pay attention to the corporate customer concentration.The regulatory authorities,companies and investors are trying together to avoid excessive stock price volatility brings profit loss to companies and investors as much as possible. |
