By calculating the mutual information of stock indexes of 10 primary industry sectors in China, this paper analyzes the dependence relationship among Chinese stock sectors during the COVID-19 and the dynamic evolution of the relationship by using the sliding window method. According to the actual situation of the development of COVID-19 in China, the samples were divided into three stages, namely, calm period, pandemic period, and post-pandemic period. ,e results show that the dependence relationship among Chinese stock sectors is significantly enhanced in the pandemic period, but it decreases in the post-pandemic period and the dependence structure is similar to that in the calm period. ,e industrials sector is most closely connected with other sectors in the pandemic period. ,e information technology sector and telecommunication services sector maintain strong dependence in the three periods and share little contact with other sectors. In the pandemic period, the dependence between the consumer staples sector and other sectors is significantly enhanced, and consumer staples sector and health care sector maintain a strong dependence. From the results of the sliding window, the Chinese stock market is sensitive to the impact of COVID-19, but the duration of the impact on the dependence among the stock sectors is not long.
1. Introduction
At the beginning of 2020, the outbreak of COVID-19 caused global panic. It is reported by WHO that up to September 1st, 2020, there have been 25,327,098 confirmed cases of COVID19, including 848,255 deaths globally. Since the outbreak of COVID-19, in order to effectively curb the spread of the pandemic, many countries have implemented a series of necessary measures, including shutdown of the production and business and home isolation. ,e implementation of these strict measures has brought a great impact on the economic development and the operation of enterprises. At present, there have been some studies about the impact of COVID-19 on world economic and social development. Studies have found that even in the early stages of COVID-19, its impact on the real economy has already been reflected [1], the pandemic has negatively affected the trade, tourism, and transportation, and it increased the unemployment rate [2]; even some studies showed that the global spread of COVID-19 had made a similar impact to an economic crisis [3].
