17 CFR § 4.30 - Prohibited activities.
(a) Except as provided in paragraph (b) of this section, no commodity trading advisor may solicit, accept or receive from an existing or prospective client funds, securities or other property in the trading advisor's name (or extend credit in lieu thereof) to purchase, margin, guarantee or secure any commodity interest of the client.
(b) The prohibition in paragraph (a) of this section shall not apply to:
(1) A futures commission merchant that is registered as such under the Act;
(2) A leverage transaction merchant that is registered as a commodity trading advisor under the Act;
(3) A retail foreign exchange dealer that is registered as such under the Act; or
(4) A swap dealer that is registered as such under the Act, with respect to funds, securities or other property accepted to purchase, margin, guarantee or secure any swap that is not cleared through a derivatives clearing organization.