How do activist groups instigate institutional change within an organizational field? Studying the global sports and apparel industry, we explore how activist groups applied different tactics over time, including conflict and collaboration, and how the accumulation of these tactics led to the build-up of pressure on firms within the industry to change their policies and activities on labor issues in their supply chains. Building on interorganizational conflict literature, we show how an industry-level approach is helpful to understand the sequential patterning (...) of tactical choices in evoking institutional change. These findings contribute to the growing literature of activists’ influence strategies. (shrink)