ABSTRACT In the absence of a global regulator, transnational financial law emerges from the combination of national laws and the contractual practices developed by networks of private, public and hybrid private-public actors who contribute to the engineering and (self-)regulation of financial services largely through contracts. The theoretical question arises whether the process of transnationalisation might determine the dominance of economic rationality over other considerations, and whether a possible nationalisation of the transnational might instead produce a repoliticisation of the economic. Against this background, the article focuses on some of the instruments of transnational financial self-regulation, and considers how these interact ambivalently with local laws and judicial practices. By looking at the role of private law institutions and considering national litigation over financial contracts in different jurisdictions, the article reveals tensions between different objectives, ultimately raising questions about the function of commercial law both within and beyond the state.