12 C.F.R. § 48.9
(a) Margin required. A national bank engaging, or offering to engage, in retail forex transactions must collect from each retail forex customer an amount of margin not less than:
(b)
(1) Form of margin. Margin collected under paragraph (a) of this section or pledged by a retail forex customer for retail forex transactions must be in the form of cash or the following financial instruments:
(2) Haircuts. A national bank must establish written policies and procedures that include:
(d) Margin calls; liquidation of position.
(1) For each retail forex customer, at least once per day, a national bank must:
(2) If, pursuant to paragraph (d)(1)(iii) of this section, the national bank determines that it has not collected margin from the retail forex customer sufficient to satisfy the requirements of this section then, within a reasonable period of time, the national bank must either:
(e) Set-off prohibited. A national bank may not: