Based on the extensive literature in the area of historical institutionalism and regulation, this article embarks on the discussion about the concept of contentious market regulation and argues that the negotiations for a Transatlantic Trade and Investment Partnership (TTIP) are emblematic of a new generation of trade liberalization. Since the negotiations started, however, the TTIP has faced the main challenge has been how to bridge the gap between the initial consensus for boosting transatlantic economic growth through trade and the increasing contestation conveyed by several actors during the negotiation process. The article finds four main factors defining the interaction between the array of players involved in the TTIP negotiation process. First, the resilience of negotiators and regulators to efficiently advance the transatlantic agenda by adapting to new demands (investment court), finding alternatives to internal resistances (federal means of liberalizing public procurement), and continuing working on technical regulations for improving market competition in the transatlantic area (automotive sector). Second, the disagreements and polarizations within the legislative bodies as well as the public opinion and social movements on both side of the Atlantic, undermining the legitimacy of the negotiation process. Third, the increasing hesitation from decision-makers to continue the TTIP negotiations, potentially eroding the effectiveness of negotiators to reached an agreement. Fourth, the more interconnected trend among preferential trade talks.