The Securities and Exchange Commission has proposed rescinding Rule 611 of Regulation NMS, the order-protection rule that has anchored US equity-market structure for two decades, in what would be the most consequential rewrite of the framework since it was adopted in 2005. Announced on 11 June 2026, the proposal would also rescind Rule 610(e), the locked-and-crossed-markets provision, and remove related defined terms in Rule 600 alongside conforming changes to other rules that reference protected quotations.
Rule 611, known formally as the order-protection rule and widely called the trade-through rule, prohibits trading venues from executing orders at prices inferior to the best displayed quotations on other exchanges, effectively making the national best bid and offer a regulatory anchor for US order routing. SEC Chairman Paul Atkins framed the proposal as overdue, arguing that after two decades the rule's unintended consequences have hindered rather than enhanced the long-term growth of the markets, and that rescinding it would simplify market structure and reduce costs while letting competition and innovation shape how equity markets evolve. Atkins dissented from Regulation NMS when it was first adopted, and the proposal reflects a long-held objection now carried into Commission policy.
The Commission's rationale rests on how far trading technology has advanced since 2005. The original framework was built when human traders were slower to update quotations and could be swayed by access-fee considerations; the SEC now argues that automated trading and modern order-routing systems can manage execution quality and avoid locked or crossed markets without a prescriptive federal mandate. In a related action the same day, the Commission extended by one year — from November 2026 to November 2027 — the compliance date for the 2024 Regulation NMS amendments covering minimum pricing increments and the reduced access-fee caps under Rule 610(c), giving the market more time while the broader rethink proceeds.
The proposal carries significant implications for finance professionals across the US trading ecosystem. Rule 611 underpins order-routing systems, smart-order-router design, exchange connectivity, market-data consumption and compliance surveillance, and its removal would unwind assumptions embedded in trading infrastructure for twenty years. Broker-dealers, exchanges, alternative trading systems, wholesalers, market makers and institutional investors would face fresh questions about best execution, displayed liquidity and venue economics, since the regulatory guarantee of intermarket price priority would no longer apply. Chief financial officers and heads of trading at affected firms would need to reassess how execution quality is measured and evidenced in a market no longer governed by a federal trade-through prohibition.
This is a decisive shift in the Commission's philosophy under Atkins toward competition, market-driven outcomes and reduced regulatory complexity. Rescinding a cornerstone rule rather than amending it indicates an appetite for structural change rather than incremental adjustment, and it places the burden on market forces and existing technology to preserve execution quality that the rule was designed to protect. Critics will question whether removing mandatory price protection could disadvantage retail and smaller investors who benefit most from the guarantee, an issue likely to dominate the consultation.
The proposal is open for public comment and is not final, so its ultimate shape will depend on the responses the Commission receives. Trading firms, exchanges and compliance teams should treat the consultation period as the moment to model the operational and best-execution consequences of a market without Rule 611, rather than waiting for a final rule. Whether the Commission proceeds as proposed or moderates the change in response to industry feedback, the direction of travel toward a lighter-touch, competition-led market structure now looks firmly set, and firms that prepare early for that environment will be better placed than those that assume the status quo holds.
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