SEC Rule 605
The disclosure of SEC-Required Order Execution Information, SEC Rule 605, requires market centers to disclose monthly data about the quality of their trade executions. Each monthly report will disclose execution qualilty data based on the previous month's trading activity.
The reports for Fidelity's market centers can be accessed below.
Pursuant to the "Joint Industry Plan; Order Approving Plan Establishing Procedures under Rule 605," the execution quality data provided in the reports must be in a standard format.
Fidelity has also prepared definitions to help you understand some of the terminology that is detailed in the above reports.
What Is a Market Center
Market centers include exchange market makers (e.g., specialist), OTC market makers, alternative trading systems, national securities exchanges (e.g., New York Stock Exchange, Inc.), or national securities associations (e.g., FINRA).
Fidelity's Market Center
Fidelity, through National Financial Services LLC, operates a market center and the 605 data can be accessed here.