At first sight, the emergence of globally accepted conduct-of-business standards for securities intermediaries, driven by international standard-setting bodies, presents itself as a showcase for successful transnational legal ordering. For some time now, such standards have come to address issues that traditionally would be addressed by fiduciary law in common law jurisdictions. Within the European Union, the relevant standards have been transposed into legislation binding on all EU Member States, irrespective of their legal environment. While clearly originating from common law principles governing fiduciary relationships, the standards thus have trickled into civil law systems, turning them into a useful object of study from the perspective of transnational law theory. Against this backdrop, the present Article explores the emanation, development, transnational dissemination, and reception of conduct-of-business standards from a European and German law perspective and looks at enforcement problems in both administrative and contract law. It demonstrates that, while the relevant law can be characterized as reflecting an emerging transnational legal order, differences between legal systems continue to exist and the process of transnationalization is far from over.