The role of competition is a frequently overlooked yet important feature for understanding the crisis-ridden nature of capitalism. One of the approaches that has consistently highlighted the nature and impact of capitalist competition in different historical periods is that of the social structure of accumulation (or SSA). Building on the understanding that intensified capitalist competition can indeed co-constitute capitalist crises, this essay further theorizes the competition-crisis nexus by linking capitalist competition to the structural problem of overaccumulation. It then reconstructs the role of intensified capitalist competition during the decline of the monopoly and post-World War II SSAs and in the current phase of neoliberal capitalism in the United States while focusing on antitrust and financial-market rules as part of the wider institutional settings that inhibit or facilitate the process of capital accumulation in each period.