This study examines why macroprudential regulation is not substantively distinct from microprudential regulation, arguing that the issue lies not merely in overlapping policy instruments but in the conceptual foundations of the micro– macro distinction itself. Macroprudential regulation is justified through its focus on systemic risk and the fallacy of composition. However, microprudential regulation has also pursued systemic stability, and the fallacy of composition is not unique to macroprudential reasoning but a general feature of both micro and macro analysis. Moreover, while macroprudential discourse relies on a Keynesian distinction between the micro and the macro, its practical regulation adopts a Lucasian microfoundation approach. The study therefore argues that macroprudential regulation tends to converge toward an extended form of microprudential regulation rather than constituting an independent regulatory paradigm.