The paper is all about the banking mergers going in the United States because the last decade the Americans witnessed number of mega-mergers in the banking industry of United States. Among those mergers, Bank of America acquisitions of Fleet Bank, MBNA and U.S. Trust are the major acquisitions. Therefore, in this paper the focus is on highlighting the short run potential cost benefits of these mergers, especially in a scenario where $300 billion national bank more likely to be more efficient than $30 billion regional or state-based bank. Secondly, the other important question arises is that whether these mergers ...