A strong relationship has always been suggested between fluctuations in stock prices and news of mergers and acquisitions. Although, there is definitely action in the prices of stocks around the days when mergers are announced, but they may not be significant in determining the reason for this particular behavior. The book testifies to the market efficiency with respect to mergers and acquisitions announcements, using an event study methodology. This methodology has been applied to analyze the response of financial markets to changes in the banking industry as a result of Mergers and Acquisitions. A merger or an acquisition is assumed to create value if the returns on the shares of the acquirers and the targets increase on the announcement of the merger. In this book, returns on the stocks of banks are compared to the market returns in order to study the effects of announcements of bank mergers on stock values in Europe.