Notice to Members NTM2017-21

Date: April 7, 2017
Re: Audit Trail Migration
Effective Date: April 10, 2017

OneChicago, LLC (“OneChicago”) is issuing this Notice to Members (“NTM”) 2017-21 to inform market participants that starting on April 10, 2017, OneChicago will begin migrating the customer audit trail to Market participants currently downloading audit trail reports from the exchange website ( must register for an SFTP account for accessing their firm’s audit trail reports.


Below are further details regarding audit trail changes:

  1. Effective April 10, 2017 the exchange will begin migrating audit trail services for firms. All firms must be migrated by July 10, 2017 as firm audit trail directories located on will be decommissioned as of this date.
  1. All audit trail subscriptions available at the new location will be subscribed to and disseminated by trading session username rather than risk group.
  1. The file naming conventions have changed. Additional information regarding the session audit trail file is located here. The new file naming convention is as follows:


(Where username is the exchange assigned trading session username)

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