The U.S. Securities & Exchange Commission’s Division of Trading and Markets hosted a Roundtable on Trade-Through Prohibitions to gather market input on the future of the Regulation NMS trade-through framework, particularly Rule 611. The discussion is intended to inform the Commission’s next steps, including whether the current trade-through prohibitions and their exceptions remain fit for purpose and how they compare with other investor-protection mechanisms such as the duty of best execution. The Division framed Rule 611 as part of a broader set of interconnected market structure choices, including access fee restrictions and market data standardization, and signalled that the topic would be explored with public input and potentially further roundtables. The agenda included a presentation from the Office of Analytics and Research drawing on recently published data for NMS stocks and listed options, covering trade-through rates and related indicators such as broker-dealer routing patterns to exchanges and changes in displayed liquidity over the last decade, as well as longer-run changes in options market structure. Panels were structured around experience with trade-through prohibitions over the past 20 years, their role in today’s automated and connected markets, and potential paths forward.