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Computer-to-computer interface (CTCI) is a method by which Nasdaq subscribers can enter transactions, such as Nasdaq Market Center orders and trade reports, from their computer systems to Nasdaq's computer systems without using a Nasdaq Workstation. The CTCI interface is based on the Common Message Switch protocol.

Benefits & Features

The Nasdaq CTCI protocol supports the following applications:


  • Order entry, modify, cancel
  • Unsolicited messages (UM), including order status and execution reports

Trade Reporting

  • Trade action/update and contra
  • Clearing broker trade action
  • Trade correction
  • Unsolicited messages including sizable, blockbuster, break, exceed and fallback


  • Order entry, cancel and cancel/replace
  • Order confirm report
  • Cancel and cancel/replace confirmation report
  • Unsolicited messages of execution, cancel/reject and confirmation

Nasdaq Fund Network (NFN)

Nasdaq is currently able to support IBM WebSphere MQ over the CTCI TCP/IP interface connection. IBM WebSphere MQ, a message queue middleware that extends business applications and enables them to communicate with one another. It also offers customers the ability to incorporate different systems into a common messaging infrastructure. CTCI TCP/IP customers may implement WebSphere MQ software to facilitate interaction between their CTCI and other internal systems.

Please visit our MQ Subscriber resource page for more information regarding IBM WebSphere MQ over the CTCI TCP/IP interface.


Who Can Participate

All Nasdaq market participants, including market makers, order-entry firms and ECNs can participate.

How to Subscribe

Nasdaq market participants can subscribe for new connectivity or update an existing service by completing the Nasdaq Port Request Form (PDF) and fax it to Nasdaq Subscriber Services at +1 212 231 5426.

To Subscribe to FINRA TRACE via CTCI:

Complete the Nasdaq Port Request Form (PDF) and if you haven’t done so already you will be required to sign the Nasdaq US Services agreement.

  • fax both to Nasdaq Subscriber Services at +1 212 231 5426.
  • All other TRACE information and agreements are found on the FINRA website.

FINRA Trade Reporting and Compliance Engine (TRACE).

Additional Resources


Technical Support

Contact Information