The global investment landscape has been utterly transformed by the growth of passive investing, which has helped lower costs and improve outcomes. As the balance of power has shifted, a few index providers now control share and dictate terms, giving rise to a new set of concerns. Meanwhile, investors face a dizzying array of options that includes not just traditional market exposure benchmarks, but also rules-based passive strategies and environmental, social, and governance-screened indices. Just as traditional beta has become commoditized, differentiated beta has become the new active. When is it ‘smart’ to research beta? How ‘sustainable’ is indexing really?