The European Union has long been an important driver for the integration of fnancial markets in Europe. The goal of this article is to map how the current and future legal infrastructure in respect of the investigation, prosecution and punishment of market abuse rules supports the central assumption of the EU legislature that, in order to offer a comprehensive package in the fight against market abuse, a level playing field throughout the EU is necessary. Although good progress has been made with the proposals for a new regulation and directive on market abuse, it is our opinion that these proposals still do not sufficiently take account of the fact that highly integrated financial markets also need highly integrated law enforcement structures and powers, regardless of the organizational statute of the national authorities involved (criminal or administrative).