This work is an investigation of the consequences of stock exchange M&A transactions on the market, the wealth of the stock exchanges, companies listed on the exchanges involved in the deal, brokers and traders, investors, and governments. The research question chosen is based on the current issue in corporate finance, and a phenomenon called the seventh wave of M&As. The research is based on information regarding 219 transactions completed during the period between 1985 and 2015, and the changes in the leading stock exchange indexes' trading volumes and prices. The variety of methods used (T-test, and the three types of regressions: OLS, Poisson, and Probit) helped to obtain the unbiased outcomes. The results of the hypotheses testing make the research relevant in the current financial market situation, and valuable because of the potential use of its findings.