Does the performance of banks improve or worsen when banks enter into new business activities? And does it matter which activities a bank expands into, or retreats from, and when that decision is made? These important questions have remained unaddressed due to a lack of data. In a recent publication, we used a unique data set detailing the organizational structure of the entire population of U.S. bank holding companies (BHCs). In this post, we draw on that research to show that while scope expansion on average hurts performance, entering into activities that are highly synergistic with core banking at a given point in time yields net performance benefits.