The variation in national regulatory responses to the recent global financial crisis has been considerable. This article explores this variation using new data on conditions in 30 different OECD countries between 2009 and 2012. Using a mixed-method approach which employs both fuzzy-set qualitative comparative analysis and logistic regression, we test a number of hypotheses regarding regulatory response patterns in the banking sector. Our findings suggest that while state intervention during the financial crisis was a necessary condition for a significant regulatory response, ‘financialization’, operationalized here as the structural dominance of the financial sector in the economy, plays a more important role. We show that financialization is both a sufficient condition and a good predictor of a significant regulatory response, and point to possible causal explanations for this surprising pattern.