Skip to main content
Technical Notice

FINRA Developer API Service Available for OTC Transparency Data

November 08, 2019

As announced in Regulatory Notice 19-21, FINRA is expanding the summary data relating to over-the-counter (OTC) equity trading that FINRA publishes on its website. This expansion includes:

  • new monthly aggregate block-size trading data for OTC trades in NMS stocks executed outside an alternative trading system (ATS) on a one-month delayed basis; and
  • aggregate non-ATS volume for all firms by eliminating the existing de minimis exception.

The date for this information to be available is Monday, December 2, 2019.

This data will be available on the OTC Transparency website ( as well as via an Application Programming Interface (API). 

As part of its multi-year Digital Experience Transformation, FINRA has launched an API Developer Center ( to support automation. The API Developer Center website includes information designed to assist clients interested in using API technology to gain access to the aggregated OTC data. The Implementation Process is outlined on the site and includes the steps needed to access the data.

The Market Transparency link includes unique datasets for the OTC (ATS & Non-ATS) Transparency data. The available API endpoints provide a mechanism to retrieve this data using a machine-to-machine interface.  As part of the aforementioned expansion, FINRA has also updated the  OTC Transparency Data Website User Guide .

If you have questions regarding this notice, please contact FINRA Business Services or call (866) 953-4672. Questions in relation to the API Developer Center can be sent to API Developer.