15 U.S.C. § 78g

(a) Rules and regulations for extension of credit; standard for initial extension; undermargined accounts For the purpose of preventing the excessive use of credit for the purchase or carrying of securities, the Board of Governors of the Federal Reserve System shall, prior to October 1, 1934 , and from time to time thereafter, prescribe rules and regulations with respect to the amount of credit that may be initially extended and subsequently maintained on any security (other than an exempted security or a security futures product). For the initial extension of credit, such rules and regulations shall be based upon the following standard: An amount not greater than whichever is the higher of— (1) 55 per centum of the current market price of the security, or (2) 100 per centum of the lowest market price of the security during the preceding thirty-six calendar months, but not more than 75 per centum of the current market price. Such rules and regulations may make appropriate provision with respect to the carrying of undermargined accounts for limited periods and under specified conditions; the withdrawal of funds or securities; the substitution or additional purchases of securities; the transfer of accounts from one lender to another; special or different margin requirements for delayed deliveries, short sales, arbitrage transactions, and securities to which paragraph (2) of this subsection does not apply; the bases and the methods to be used in calculating loans, and margins and market prices; and similar administrative adjustments and details. For the purposes of paragraph (2) of this subsection, until July 1, 1936 , the lowest price at which a security has sold on or after July 1, 1933 , shall be considered as the lowest price at which such security has sold during the preceding thirty-six calendar months. (b) Lower and higher margin requirements Notwithstanding the provisions of subsection (a) of this section, the Board of Governors of the Federal Reserve System, may, from time to time, with respect to all or specified securities or transactions, or classes of securities, or classes of transactions, by such rules and regulations (1) prescribe such lower margin requirements for the initial extension or maintenance of credit as it deems necessary or appropriate for the accommodation of commerce and industry, having due regard to the general credit situation of the country, and (2) prescribe such higher margin requirements for the initial extension or maintenance of credit as it may deem necessary or appropriate to prevent the excessive use of credit to finance transactions in securities. (c) Unlawful credit extension to customers (1) Prohibition It shall be unlawful for any member of a national securities exchange or any broker or dealer, directly or indirectly, to extend or maintain credit or arrange for the extension or maintenance of credit to or for any customer— (A) on any security (other than an exempted security), except as provided in paragraph (2), in contravention of the rules and regulations which the Board of Governors of the Federal Reserve System (hereafter in this section referred to as the “Board”) shall prescribe under subsections (a) and (b); or (B) without collateral or on any collateral other than securities, except in accordance with such rules and regulations as the Board may prescribe— (i) to permit under specified conditions and for a limited period any such member, broker, or dealer to maintain a credit initially extended in conformity with the rules and regulations of the Board; and (ii) to permit the extension or maintenance of credit in cases where the extension or maintenance of credit is not for the purpose of purchasing or carrying securities or of evading or circumventing the provisions of subparagraph (A). (2) Margin regulations (A) Compliance with margin rules required It shall be unlawful for any broker, dealer, or member of a national securities exchange to, directly or indirectly, extend or maintain credit to or for, or collect margin from any customer on, any security futures product unless such activities comply with the regulations— (i) which the Board shall prescribe pursuant to subparagraph (B); or (ii) if the Board determines to delegate the authority to prescribe such regulations, which the Commission and the Commodity Futures Trading Commission shall jointly prescribe pursuant to subparagraph (B). If the Board delegates the authority to prescribe such regulations under clause (ii) and the Commission and the Commodity Futures Trading Commission have not jointly prescribed such regulations within a reasonable period of time after the date of such delegation, the Board shall prescribe such regulations pursuant to subparagraph (B). (B) Criteria for issuance of rules The Board shall prescribe, or, if the authority is delegated pursuant to subparagraph (A)(ii), the Commission and the Commodity Futures Trading Commission shall jointly prescribe, such regulations to establish margin requirements, including the establishment of levels of margin (initial and maintenance) for security futures products under such terms, and at such levels, as the Board deems appropriate, or as the Commission and the Commodity Futures Trading Commission jointly deem appropriate— (i) to preserve the financial integrity of markets trading security futures products; (ii) to prevent systemic risk; (iii) to require that— (I) the margin requirements for a security future product be consistent with the margin requirements for comparable option contracts traded on any exchange registered pursuant to section 78f(a) of this title ; and (II) initial and maintenance margin levels for a security future product not be lower than the lowest level of margin, exclusive of premium, required for any comparable option contract traded on any exchange registered pursuant to section 78f(a) of this title , other than an option on a security future; except that nothing in this subparagraph shall be construed to prevent a national securities exchange or national securities association from requiring higher margin levels for a security future product when it deems such action to be necessary or appropriate; and (iv) to ensure that the margin requirements (other than levels of margin), including the type, form, and use of collateral for security futures products, are and remain consistent with the requirements established by the Board, pursuant to subparagraphs (A) and (B) of paragraph (1). (3) Exception This subsection and the rules and regulations issued under this subsection shall not apply to any credit extended, maintained, or arranged by a member of a national securities exchange or a broker or dealer to or for a member of a national securities exchange or a registered broker or dealer— (A) a substantial portion of whose business consists of transactions with persons other than brokers or dealers; or (B) to finance its activities as a market maker or an underwriter; except that the Board may impose such rules and regulations, in whole or in part, on any credit otherwise exempted by this paragraph if the Board determines that such action is necessary or appropriate in the public interest or for the protection of investors. (d) Unlawful credit extension in violation of rules and regulations; exceptions to application of rules, etc. (1) Prohibition It shall be unlawful for any person not subject to subsection (c) to extend or maintain credit or to arrange for the extension or maintenance of credit for the purpose of purchasing or carrying any security, in contravention of such rules and regulations as the Board shall prescribe to prevent the excessive use of credit for the purchasing or carrying of or trading in securities in circumvention of the other provisions of this section. Such rules and regulations may impose upon all loans made for the purpose of purchasing or carrying securities limitations similar to those imposed upon members, brokers, or dealers by subsection (c) and the rules and regulations thereunder. (2) Exceptions This subsection and the rules and regulations issued under this subsection shall not apply to any credit extended, maintained, or arranged— (A) by a person not in the ordinary course of business; (B) on an exempted security; (C) to or for a member of a national securities exchange or a registered broker or dealer— (i) a substantial portion of whose business consists of transactions with persons other than brokers or dealers; or (ii) to finance its activities as a market maker or an underwriter; (D) by a bank on a security other than an equity security; or (E) as the Board shall, by such rules, regulations, or orders as it may deem necessary or appropriate in the public interest or for the protection of investors, exempt, either unconditionally or upon specified terms and conditions or for stated periods, from the operation of this subsection and the rules and regulations thereunder. (3) Board authority The Board may impose such rules and regulations, in whole or in part, on any credit otherwise exempted by subparagraph (C) if it determines that such action is necessary or appropriate in the public interest or for the protection of investors. (e) Effective date of this section and rules and regulations The provisions of this section or the rules and regulations thereunder shall not apply on or before July 1, 1937 , to any loan or extension of credit made prior to June 6, 1934 , or to the maintenance, renewal, or extension of any such loan or credit, except to the extent that the Board of Governors of the Federal Reserve System may by rules and regulations prescribe as necessary to prevent the circumvention of the provisions of this section or the rules and regulations thereunder by means of withdrawals of funds or securities, substitutions of securities, or additional purchases or by any other device. (f) Unlawful receipt of credit; exemptions (1) It is unlawful for any United States person, or any foreign person controlled by a United States person or acting on behalf of or in conjunction with such person, to obtain, receive, or enjoy the beneficial use of a loan or other extension of credit from any lender (without regard to whether the lender’s office or place of business is in a State or the transaction occurred in whole or in part within a State) for the purpose of (A) purchasing or carrying United States securities, or (B) purchasing or carrying within the United States of any other securities, if, under this section or rules and regulations prescribed thereunder, the loan or other credit transaction is prohibited or would be prohibited if it had been made or the transaction had otherwise occurred in a lender’s office or other place of business in a State. (2) For the purposes of this subsection— (A) The term “United States person” includes a person which is organized or exists under the laws of any State or, in the case of a natural person, a citizen or resident of the United States; a domestic estate; or a trust in which one or more of the foregoing persons has a cumulative direct or indirect beneficial interest in excess of 50 per centum of the value of the trust. (B) The term “United States security” means a security (other than an exempted security) issued by a person incorporated under the laws of any State, or whose principal place of business is within a State. (C) The term “foreign person controlled by a United States person” includes any noncorporate entity in which United States persons directly or indirectly have more than a 50 per centum beneficial interest, and any corporation in which one or more United States persons, directly or indirectly, own stock possessing more than 50 per centum of the total combined voting power of all classes of stock entitled to vote, or more than 50 per centum of the total value of shares of all classes of stock. (3) The Board of Governors of the Federal Reserve System may, in its discretion and with due regard for the purposes of this section, by rule or regulation exempt any class of United States persons or foreign persons controlled by a United States person from the application of this subsection. (g) Effect of bona fide agreement for delayed delivery of mortgage related security Subject to such rules and regulations as the Board of Governors of the Federal Reserve System may adopt in the public interest and for the protection of investors, no member of a national securities exchange or broker or dealer shall be deemed to have extended or maintained credit or arranged for the extension or maintenance of credit for the purpose of purchasing a security, within the meaning of this section, by reason of a bona fide agreement for delayed delivery of a mortgage related security or a small business related security against full payment of the purchase price thereof upon such delivery within one hundred and eighty days after the purchase, or within such shorter period as the Board of Governors of the Federal Reserve System may prescribe by rule or regulation.