“This article examines the principal legal, policy, and theoretical implications of a transformative – but so far unrecognized – change in the banking industry: the emergence, over the last decade, of U.S. financial conglomerates as leading global merchants in physical commodities, including crude and refined oil products, natural gas, coal, base metals, and wholesale electricity. Historically, one of the core principles of U.S. bank regulation has been the separation of banking from commerce. Several statutes – including the National Bank Act of 1863, the Bank Holding Company Act of 1956, the Gramm-Leach-Bliley Act of 1999, and even the Dodd-Frank Act of 2010 – affirm this foundational principle, which generally prohibits banks and bank holding companies from conducting commercial (i.e., non-financial) activities. Notwithstanding these statutory restrictions, however, large U.S. bank holding companies – notably, Morgan Stanley, Goldman Sachs, and JPMorgan – have since the early 2000s been moving aggressively into the purely commercial businesses of mining, processing, transporting, storing, and trading a wide range of vitally important physical commodities. And, equally surprisingly, it is virtually impossible under the current system of public disclosure and regulatory reporting to understand the true nature and scope of these institutions’ commodity activities. This article puts together the first comprehensive account to date of what appears to be publicly knowable about the nature and scope of U.S. banking organizations’ physical commodities activities and analyzes the existing legal and regulatory framework for conducting such activities. Based on this analysis, the article advances several claims. As a matter of legal doctrine, the article argues that the quiet transformation of U.S. bank holding companies into global commodity merchants effectively nullifies the foundational principle of separation of banking from commerce. It further argues that the currently existing statutory framework does not provide a sufficiently robust structure for the regulation and supervision of banking organizations’ extensive commercial operations in global commodity and energy markets.  As a normative matter, the article argues that banking organizations’ physical commodities activities raise potentially serious public policy concerns. These activities threaten to undermine the fundamental policy objectives that underlie the principle of separating banking from commerce: ensuring the safety and soundness of the U.S. banking system, maintaining a fair and efficient flow of credit in the economy, protecting market integrity, and preventing excessive concentration of economic power. In addition, banking organizations’ expansion into physical commodities implicates a distinct set of policy concerns relating to potential new sources and transmission channels of systemic risk, the integrity and efficacy of the regulatory process, and the governability of financial markets and institutions. Finally, the article argues that these developments in banks’ activities raise fundamental theoretical and conceptual questions about the very nature and social functions of financial intermediation. A factually-grounded examination of large financial institutions’ physical commodity activities lays a necessary conceptual foundation for potentially reconfiguring the entire system of financial services regulation.”