This article focuses on the transformatory potential of macroprudential ideas following the financial crash of 2008, examining how they are being mediated by existing institutional contexts and how and why the task of building a new body of technical macroprudential knowledge is proceeding slowly. It is argued that the movement toward a form of macroprudential regulation has a distinctly incremental dynamic that means any macroprudential transformation will be a gradual process that is likely to span a decade or more. Using Peter Hall's framework of three orders of policy change across substantive and temporal dimensions, the article argues that the macroprudential ideational shift can be compared to third order change. In this sense, it was intellectually radical and took place rapidly in a period of around six months. However, intellectual radicalism does not automatically translate into a radical change in regulatory practice, because of a variety of countervailing political, institutional, and informational variables. In this respect, the task of developing first and second order macroprudential policy is proving to be a much more politically contested process. Furthermore, macroprudential policy is being developed by cautious technocrats who rely on the gradual accumulation of data and evidence to justify policy. The result is a distinctly incremental dynamic to macroprudential policy development that displays many of the features of a process that historical institutionalists refer to as "layering."