17 CFR 38.607: Direct access.

A designated contract market that permits direct electronic access by customers (i.e., allowing customers of futures commission merchants to enter orders directly into a designated contract market's trade matching system for execution) must have in place effective systems and controls reasonably designed to facilitate the FCM's management of financial risk, such as automated pre-trade controls that enable member futures commission merchants to implement appropriate financial risk limits. A designated contract market must implement and enforce rules requiring the member futures commission merchants to use the provided systems and controls.