A handful of broker-dealers have publicly posted their 'Form ATS,' which describes some operations of their dark pools. The Barclays Form ATS describes how subscribers to the dark pool can supply "conditional orders" on stocks. These orders allow the subscriber to "decide" whether to execute against incoming customer orders from the Braclays Smart Order Router ("SOR"). http://investmentbank.barclays.com/...form-ats-for-barclays-lx-march-2013-625kb.pdf "Conditional Order Negotiations: The Barclays ATS provides a process for negotiating trades based on conditional parameters, called the Conditional Order Negotiation. The Conditional Order Negotiation operates as follows: A subscriber may submit to the ATS via the electronic order entry connection, the SOR, or LMX, a message, called a "Conditional Order", which describes the subscriber's potential interest in a trade. Specifically, the message describes the price, size, side and symbol of the subscriber's interest. The message is marked as conditional and therefore is not executable. Instead, if and when an eligible contra-side order that could match against the Conditional Order is submitted to the ATS, the ATS will send to the subscriber, the smart order router or LMX (whichever sent the Conditional Order to the ATS) a message which indicates that a potential match has been found ("Conditional Invitation"). The Conditional Invitation describes the price, size, side and symbol of the potentially matching interest. The subscriber, the SOR or LMX (depending on how the Conditional Order was entered into the ATS) then has the option to send a "firm-up" order in response to the Conditional Invitation. This firm-up order is treated as any other order sent to the ATS (as previously described here in Exhibit F), including abiding by price/tier/time priority. The following sets forth an example for how the Conditional Order Negotiation would operate: (1) Subscriber A submits a Conditional Order to the ATS indicating an interest in buying 1000 shares of ABC at $10. (2) Shortly thereafter, Subscriber B submits a Conditional Eligible Firm Order (as defined below) to the ATS indicating an interest in selling 1000 shares of ABC at $10. (3) The ATS sends a Conditional Invitation to Subscriber A indicating that a potential match has been found. (4) Subscriber A decides to submit a firm-up order to the ATS. (5) The ATS processes the firm-up order in accordance with the ATS's standard price/time/priority requirements. Therefore, subject to the execution algorithm, and depending on whether the Conditional Eligible Firm Order has not been cancelled or executed, the firm-up order may execute against the Conditional Eligible Firm Order. As with all other order and execution information sent to the ATS, Conditional Orders and Conditional Invitations sent during the Conditional Order Negotiations are not disseminated to any other subscribers, third-parties, or personnel within Barclays, although compliance and technology personnel for the Barclays ATS may access this information for their assigned compliance or technology purposes. Also, similar to any other order type sent to the Barclays ATS, Conditional Orders will comply with all rules and regulations applicable to such orders within the ATS."
Yes, Barclays amended their Form ATS in 2013. They decided to make the info public in June 2014. Other firms that have made their Form ATS public include: IEX: https://s3.amazonaws.com/iextrading/docs/Form+ATS+Redacted.pdf Goldman Sachs: http://www.goldmansachs.com/media-relations/in-the-news/current/pdf-media/gs-form-ats-amendment.pdf KCG: https://www.kcg.com/uploads/documents/KnightMatchFormATS.pdf Liquidnet: http://www.liquidnet.com/uploads/ATS_(Negotiation)_Form-Exhibit_CLEAN_4feb2015.pdf ITG: http://www.itg.com/marketing/ITG-Form-ATS-for-POSIT-Dec-2013.pdf JP Morgan: https://www.jpmorgan.com/cm/BlobSer...=private&blobcol=urldata&blobtable=MungoBlobs Weeden & Co.: http://www.weedenco.com/sitedocs/Form-ATS.pdf