In major markets around the world there has been a growing trend towards unification of responsibility for the regulation of banks, securities markets, and insurance companies. Countries where a unified agency has recently assumed regulatory responsibilities for all financial institutions include the United Kingdom ("U.K."), Japan, and Korea. The United Kingdom enacted the Financial Services and Markets Act 2000 (FSMA), which respond to some common challenges faced in twenty-first century financial regulation. That is, the U.K. has sought to match the unitary nature of its institutional arrangements for financial regulation with an integrated legal framework. Recently, there is an argument that we had better enact ``an integrated financial`` act such as FSMA. This article tries to review the argument critically and offers some observations. Throughout the world, there is wide variety in the existing institutional arrangements and, despite the current interest in the single regulator model, its adoption in practice remains relatively rare. To take an ``integrated financial`` act like the FSMA would face practical and theoretical hurdles that currently appear insurmountable. The recognition that national institutional arrangements evolve under the influence of local factors, as well as global trends in financial markets, suggests that there is no one ideal model that is universally applicable.