This book provides the first comprehensive examination of the regulation of the money market fund sector. In consideration of the current regulatory uncertainties in the sector, this book provides practical help to legal and market practitioners by setting out regulations governing money market funds in the EU and in the US. Providing a comparative approach, analyzing the regulatory environment in the EU and in the US, the book outlines what is required to determine portfolio management and regulatory compliance issues. In doing so, it determines whether a particular analytical approach issufficiently credible vis-a-vis comparative benchmarks, which is increasingly pivotal in the contemporary setting of the global financial market. Contributing authors offer their interpretations of legal rules and relevant guidelines as well as commentaries, checklists, and practice examples. Divided into three parts; parts one and two cover money market fund development and regulation in the EU and in the US, respectively. Part three provides a comparative analysis of US and EU regulatory models, money market fund ratings, money market funds outside the US and EU and systemic risk regulation. Given the current issues surrounding money market fund regulation, this book is a vital and timely resource offering a comprehensive comparative analysis and rigorous account of money market funds on both sides of the Atlantic.