Rule 605 Disclosure of Order Execution Information

SEC Rule 605 (formerly Rule 11Ac1-5) requires that market centers that trade national market system securities disclose monthly electronic reports about the quality of their executions on a stock-by-stock basis based on the previous month’s trading activity. MEMX Rule 605 reports are available for download below.

This information may not be directly comparable to data displayed by other market centers due to differences in market structures and computation methods. While MEMX has used reasonable efforts to prepare these reports in compliance with Rule 605, these statistics have not been audited and may contain errors. Accordingly, any decision about whether to send orders to MEMX should not be based solely on these statistics.

MEMX has iteratively updated reporting methodology as follows: 

  • The treatment of post-only orders was updated to better align with other market centers as of September 2022.
  • The order type code computation method for At-the-Quote Limit Orders and Marketable Limit Orders was updated as of May 2022.
  • The computation method for average realized spread and average effective spread was updated as of January 2022.