The term national bank can refer to various central monetary authorities or historical commercial entities across the world. In the United States, commercial institutions operating under a national bank charter are regulated by the Office of the Comptroller of the Currency and have largely been consolidated through interstate banking mergers into massive nationwide financial conglomerates. Globally, national banks function as central monetary authorities responsible for formulating national interest rate policies, managing currency reserves, regulating commercial banking sectors, and maintaining overall macroeconomic financial stability.