Digital information and communications technologies (ICTs) are transforming capital markets. The integration of capital markets is seen as one such area of transformation. The research presented in this article studies one integration initiative that took shape around the proposed combination of a number of key European securities marketplaces through the development of a cross-border settlement system. Taking a sociotechnical approach, the research presents the positions of the key actants identified in relation to key controversies regarding the development of the settlement system and shows how the relations between the controversies and the positions of the actants involved in them evolve. By examining the role of ICTs in the evolution of these relations, the study seeks to illuminate the complex causalities between the social and technical aspects of cross-border capital market integration. The article argues that in addition to enabling the interconnecting of an expanded set of transacting parties, ICTs bring important cognitive dimensions that enable the inspiration, planning, and foresight necessary for both developers and market participants to formulate their plans, strategies, and positions vis-à-vis the expanded and transformed marketplace arrangements