17 CFR 1.24: Segregated funds; exclusions therefrom.

Money held in a segregated account by a futures commission merchant shall not include: (a) Money invested in obligations or stocks of any derivatives clearing organization or in memberships in or obligations of any contract market; or

(b) Money held by any derivatives clearing organization which it may use for any purpose other than to purchase, margin, guarantee, secure, transfer, adjust, or settle the contracts, trades, or commodity options of the futures customers of such futures commission merchant.