The SEC and the European Central Bank (ECB) announced the signing of a Memorandum of Understanding (MOU) to consult, cooperate and exchange information in connection with the supervision, enforcement and oversight of certain security-based swap dealers and major security-based swap participants that are registered with the SEC, are supervised by the ECB and participate in the Single Supervisory Mechanism (SSM). In addition, the MOU will support the SEC’s oversight of the operation of substituted compliance orders that the Commission has issued for security-based swap entities in France and Germany, as well as any future substituted compliance orders for those firms in other E.U. Member States that participate in the SSM. This article provides an overview of the MOU, discusses the relevance of the collapse of family office Archegos Capital Management to the MOU and outlines the key takeaways from the MOU for hedge fund managers that engage in security-based swap transactions. See “European Central Bank Official Regards Hedge Fund Leverage As Risk to Financial System” (Mar. 24, 2016).