Wan, Ying2024-01-242024-01-242023-12https://hdl.handle.net/20.500.12087/269A dissertation submitted in partial fulfillment of the requirements for the degree Doctor of Business AdministrationThis research evaluated the correlation between COVID-19 and economic variables with the stock market performance, the changing trends in industry sectors, and individual company performance for investment decisions. COVID-19, economic policies, and variables were cointegrated and moved in a unidirectional way that affected the volatility and severely damaged the efficiency of the U.S. stock market. Moreover, COVID-19 and the subsequent government policies affected some industries and companies more than others. This research adopted quantitative method to test the correlation between COVID-19 and economic variables with the index return through a hierarchical regression model and Pearson correlation test. The research also used qualitative method with document and case analysis to study the stock market reaction to COVID-19 at the industry and company levels. The research comprised an economic analysis by collecting data on COVID-19 case numbers, interest rates, and other economic variables to test their correlation, an industry analysis by studying the annual reports of S&P 100 index companies to explore how COVID-19 affected industries differently, and a company analysis of the qualitative and quantitative factors to evaluate investment decision. The research had implications for both investors and policymakers.en-USBusiness AdministrationThesis