Abstract

Since 2012, restructuring of the securities market has been the primary strategic project in Vietnam – the top-performing Asian economy in recent years, and several regulatory changes have been made to enhance the market stability and efficiency as well as facilitate its sustainable development. This study strives for investigating the Vietnamese stock market efficiency and evaluating the impacts of market behaviours on listed companies due to recent regulatory changes in the stock market. The mixture of quantitative, qualitative, and documentary data is utilised to meet the research requirements. The quantitative analysis in this study show that HOSE is firmly efficient while HNX is inefficient. On this subject, the managers and experts in the stock market consistently support that HOSE has better market efficiency than HNX. In the key factors of the Vietnamese stock market efficiency, the access to the information and the market valuation are the two most crucial ones from the viewpoint of the managers of the listed companies, the officer of HOSE, and the experts in this field. In comparison with the existing studies on this stock market efficiency, there is an improvement of the Vietnamese stock market efficiency in general and the market efficiency of HOSE in specific. The informational efficiency of this stock exchange market is enhanced from the inefficiency to the weak form efficiency. The findings in this research consistently show that recent regulatory changes designed to improve the operations and the efficiency of the Vietnamese market have been effective. Listing, trading, and conforming to the current regulations in the stock market create tremendous opportunities and beneficial impacts on the performance of listed companies regarding business management and development, enhancement of funds as well as value and brand growth. Furthermore, the current regulations in the market and especially on HOSE greatly encourage and support the listed companies, but few limitations exist from the perspectives of the managers of listed companies on HNX and the experts in the stock market. The original contribution of this study is providing a theoretical framework to examine the responses of the stock market efficiency to crucial regulatory changes in the emerging stock exchange markets as well as evaluate its impacts and implications on the business performance. This research methodological design allows the researcher to investigate at the market level and the market participants’ levels by using the mixture of quantitative and qualitative approaches to provide a thorough understanding of the linkages between stock market efficiency and business performance in emerging markets. This study also analyses different sizes of the listed companies in various sectors in addition to the market indices to ensure the reliability and the validity of testing the Vietnamese stock market efficiency. The findings and contributions of this thesis identify major implications for financial policies and management practice to further improve the stock market efficiency and enhance the benefits of the listed companies.