Notice to Members 2017-51

Date: November 9, 2017
Re: Introduction of “Immediate or Cancel” (IOC) Orders
Effective Date: November 13, 2017

OneChicago, LLC (“OneChicago”) is issuing this Notice to Members (“NTM”) 2017-51 to inform market participants of the introduction of an “Immediate or Cancel” (IOC) Time in Force for limit orders. An IOC order is a limit order to buy or sell that must be executed immediately. Any portion of an IOC order that cannot be filled immediately will be cancelled.

The IOC order will be available in the Delta1 Front End by selecting IOC in the Time in Force field during order entry. For API users, IOC orders will be implemented by adding additional support for 59=3 (IOC) for the Time in Force value. This feature will be supported for both New Order Single and Cancel/Replace. Additional information regarding API support can be found in OneChicago’s Guide to Delta1.


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If you have any questions, please contact OneChicago Operations at (312) 883-4311 or