On June 11, 2026, the SEC took two actions that could reshape U.S. equity market structure:
The SEC also extended the compliance date by one year for the 2024 Regulation NMS amendments relating to minimum pricing increments and access fee caps, moving implementation from November 2026 to November 2027.
Together, these actions signal a fundamental shift in the Commission’s approach to equity market regulation under Chair Atkins, with an increased emphasis on competition, market-driven outcomes, and reducing regulatory complexity.
Rule 611 of Regulation NMS, adopted in 2005, requires trading centers to establish policies and procedures reasonably designed to prevent “trade-throughs”—executions at prices inferior to protected quotations displayed on other trading venues. Rule 610(e) requires exchanges and associations to maintain rules designed to prevent locked and crossed markets.
The SEC’s proposal would rescind both rules in their entirety, along with related definitions and conforming provisions throughout Regulation NMS. However, the proposal explicitly does not apply to listed options, which are governed by the Options Order Protection and Locked/Crossed Market Plan—a separate Commission-approved NMS Plan that imposes trade-through protections and locked and crossed market restrictions analogous to Rules 611 and 610(e) for equity markets.
The Commission argues that the market structure concerns that motivated Regulation NMS in 2005 have been rendered unnecessary by technological developments and changes in trading practices. According to the proposal:
Chair Atkins echoed these themes in his statement supporting the proposal, emphasizing that Regulation NMS was adopted for a different technological era and arguing that current market participants are capable of achieving best execution through market forces and modern trading infrastructure. During the original 2005 adoption of Regulation NMS, Chair Atkins, a commissioner at the time, voted against its adoption.
If adopted, the proposal could significantly alter order routing, exchange competition, and execution practices while potentially causing market disruption as the markets adjusted.
Potential effects highlighted by the SEC include:
The proposal may be particularly significant for institutional trading strategies, where market participants have long argued that Rule 611 can increase information leakage and execution costs by forcing interaction with small protected quotations across multiple venues.
The proposal also intersects with the tiered round-lot definition adopted as part of the Market Data Infrastructure (MDI) Rules in November 2025. This change has already begun to alter the practical scope of Rule 611’s protections, particularly for high-priced stocks where odd-lot quotes now represent substantial notional liquidity and, in many cases, set the effective best available price inside the NBBO.
The SEC also proposes rescinding Rule 610(e), which currently requires exchanges and associations to maintain rules designed to prevent members from displaying quotations that lock or cross protected quotations.
The Commission argues that:
Notably, while the SEC would remove the federal requirement, exchanges would remain free to retain or modify their own rules governing locked and crossed markets.
The proposal would also eliminate numerous Regulation NMS definitions that would become unnecessary if Rules 611 and 610(e) are rescinded, including:
The SEC also proposes conforming amendments to Regulation NMS, Rule 15c3-5 (“Market Access Rule”), Rule 15b9-1, and other provisions that currently reference Rule 611 or protected quotations.
In a separate action issued the same day, the SEC granted temporary exemptive relief extending implementation of the 2024 Regulation NMS amendments concerning minimum pricing increments and access fee caps until November 2027.
The extension applies to:
The Commission cited concerns regarding the cumulative impact of multiple market structure initiatives scheduled for implementation during 2026, including:
The SEC concluded that additional time was necessary to promote an orderly implementation process and reduce operational risk across the national market system.
The proposal raises a number of important issues for exchanges, broker-dealers, institutional investors, wholesalers, ATS operators, and technology vendors, including:
The SEC has requested extensive public comment on these issues, including whether rescission of Rules 611 and 610(e) should be accompanied by revisions to best execution guidance, SRO rules, and NMS plans.
Although the proposal remains subject to notice-and-comment rulemaking, it represents one of the most consequential market structure initiatives undertaken by the SEC in decades. If adopted substantially as proposed, the changes would move the U.S. equity markets away from the centralized intermarket protections that have characterized Regulation NMS since 2005 and toward a framework that relies more heavily on competition, technology, and best execution obligations.
The proposal’s 60-day comment period is expected to generate significant industry participation and could provide important insights into how market participants view the future structure of U.S. equity markets.