Objectives: Europe is one of the important markets for traditional tobacco. We analyzed the impact of exchange consolidation on securities market efficiency, so as to enable tobacco enterprises to improve the financing efficiency of the stock market and carry out transformation and
upgrading. Methods: In this work. We’re based on efficient market theory, the merger of Pan-European Stock Exchange and Oslo Stock Exchange, Norway in June 2019 is analyzed through empirical analysis. The logarithmic returns of 25 listed companies in the Oslo Stock Exchange OBX-25 index
were analyzed using OLSN Chow and KPSS tests. Results: It is found that of 72% of securities, the explanatory power of market returns for securities returns is increased, which shows significant improvement in market efficiency. The merger of stock exchanges can indeed improve the market efficiency.
In addition, through the KPSS test, it is found that the merger of stock exchanges can improve the market efficiency. As time goes by, however, the validity decreases. Conclusion: The improvement of the efficiency of the securities market will be conducive to the financing efficiency of listed
tobacco companies in the secondary market, promote the transformation of enterprises, and contribute to the tobacco control and the health of the population in Europe.