Trade and professional associations are a type of collaboration between competitors that generate several interesting and hard antitrust debates, still with diverging views on several topics. They can significantly foster competition but can also implicate serious concerns, from cartels, to concerted boycotts, exchange of sensitive information and market foreclosure. A central aspect related to these associations is countervailing power, which often allows for more flexibility on antitrust enforcement even in face of coordination of sensitive economic variables. Rising competition concerns in the labor market and EC’s recent announcement in favor of more bargaining power to liberal professionals and self-employed individuals can bring trade and professional associations back to the antitrust front of debates. Finding the right balance of countervailing power, however, is an equation that is hard to solve.