Who controls global policy debates on shadow banking regulation? We show how experts secured control over how issues in shadow banking regulation are treated by examining the policy recommendations of the Bank of International Settlements, the International Monetary Fund and the Financial Stability Board. The evidence suggests that IO experts embedded a bland reformism opposed to both strong and ‘light touch’ regulation at the core of the emerging regulatory regime. Technocrats reinforced each other’s expertise, excluded some potential competitors (legal scholars), co-opted others (select Fed and elite academic economists), and deployed measurement, mandate, and status strategies to assert issue control. In the field of shadow banking regulation, academic economists’ influence came from their credibility as arbitrageurs between several professional fields rather than their intellectual output. The findings have important implications for how we study the relationship between IO technocrats and experts from other professional fields.