SEC Proposal to Rescind Regulation NMS Rules 611 and 610(e): A Paradigm Shift in Equity Market Structure

Reference: Release No. 2026-54

Official publication: Read the full Release No. 2026-54 on the agency website

The Securities and Exchange Commission (SEC) has unveiled a transformative proposal to rescind Rule 611 and Rule 610(e) of Regulation NMS, marking one of the most significant shifts in equity market oversight since the regulation’s inception in 2005. For over two decades, Rule 611—commonly known as the Order Protection Rule or the ‘Trade-Through Rule’—has served as a cornerstone of the U.S. national market system by requiring trading centers to establish procedures to prevent ‘trade-throughs’ of protected quotations. By proposing to dismantle this mechanical protection, the Commission is signaling a move toward a more flexible, competition-driven market environment where the burden of execution quality shifts more squarely onto the fiduciary obligations of broker-dealers rather than automated regulatory mandates.

Executive Summary

• Rescission of Rule 611: The proposal seeks to eliminate the requirement that trading centers protect the best displayed prices at other exchanges, effectively ending the ‘Trade-Through’ era.
• Removal of Rule 610(e): The Commission proposes to rescind specific connectivity and access requirements that were historically tethered to the operation of Rule 611.
• Shift to Best Execution: Regulatory focus is expected to transition from mechanical price matching to a broader assessment of execution quality, including speed, likelihood of execution, and overall cost.
• Market Fragmentation Strategy: The SEC aims to address unintended consequences of the 2005 rules, specifically the proliferation of high-frequency trading strategies and complex exchange structures designed solely to capture or bypass protected quotes.
• Operational Complexity: Firms must prepare for a radical redesign of Smart Order Routers (SORs) and execution algorithms that currently rely on the ‘protected quote’ status of national securities exchanges.

What the Regulator Issued

On June 11, 2026, the Securities and Exchange Commission issued a formal proposal to amend Regulation NMS by rescinding Rules 611 and 610(e). The official announcement, SEC Press Release 2026-54, outlines a vision for a market structure that prioritizes competitive innovation over rigid price-protection mandates. The Commission noted that the market has evolved significantly since 2005, rendering the original justifications for these rules obsolete in an era of microsecond latency and deep liquidity fragmentation.

The Commission specifically highlighted that Rule 611, while originally intended to bolster investor confidence by ensuring they receive the ‘best price,’ has inadvertently incentivized market behaviors that may harm overall efficiency. In the words of the Commission, “After two decades of Rule 611, it is high time that the Commission review its unintended consequences that have hindered — rather than helped — the efficient execution of orders in a hyper-fast marketplace.”

Who Is Impacted

The proposed rescission of Rules 611 and 610(e) reaches across the entire spectrum of the equity capital markets, affecting entities that have built their business models around the current Regulation NMS framework. National Securities Exchanges (NSEs) are perhaps the most directly impacted, as the loss of ‘protected’ status for their quotations will force them to compete more aggressively on fees, latency, and unique liquidity pools rather than relying on a regulatory mandate that forces order flow to their doors. For exchanges with lower liquidity or higher latency, this change could pose an existential threat to their current volume shares.

Broker-dealers, particularly those operating Smart Order Routers and execution algorithms, will face a massive compliance and engineering undertaking. Without Rule 611, the ‘safe harbor’ of simply routing to the best displayed price is effectively removed. Firms will need to justify their routing decisions based on a multi-factorial ‘Best Execution’ standard. This will require more robust data capture and analysis to prove that bypassing a displayed price at one venue in favor of another was in the client’s best interest based on factors like fill rate or price improvement potential.

Institutional investors and asset managers will likely see a shift in how their large orders are handled. The removal of trade-through protections could allow for more creative ‘block’ trading strategies that were previously hindered by the need to clear out small, protected lots on various exchanges. Conversely, retail investors and the wholesalers who service them will need to monitor whether the lack of protected quotes leads to wider spreads or a reduction in the visible liquidity that currently anchors the public markets.

Key Dates and Deadlines

The SEC has established a standard timeline for this high-impact rulemaking process. The proposal is currently subject to a public comment period, which will remain open for 60 days following its publication in the Federal Register. Given the complexity of the changes and the significant technical debt involved in updating market infrastructure, the Commission has suggested a phased implementation period if the rules are finalized. However, at this stage, firm compliance deadlines are not specified in the release and will depend on the final rule’s adoption date, likely in late 2026 or early 2027.

Practical Action Checklist

1. Technical Audit of Smart Order Routers (SORs): Conduct a comprehensive review of current routing logic to identify dependencies on Rule 611 ‘protected quote’ status.
2. Revision of Best Execution Policies: Update internal compliance manuals to reflect a shift from mechanical price-matching to a fiduciary-based execution quality standard.
3. Data Infrastructure Assessment: Evaluate whether current trade data capture is sufficient to justify routing decisions in an environment where bypassing a displayed better price is legally permissible but requires a rational basis.
4. Exchange Relationship Review: Re-assess participation on smaller or ‘inverted’ exchanges that may lose significant volume once their quotes are no longer protected.
5. Algorithm Re-Calibration: Work with quantitative teams to test how execution algorithms perform in a ‘non-protected’ market simulation, specifically focusing on slippage and fill rates.
6. Comment Letter Participation: Engage with industry trade groups or legal counsel to draft comment letters focusing on the technical challenges of removing Rule 610(e) connectivity requirements.
7. Client Communication Strategy: Prepare disclosures for institutional clients explaining how the removal of trade-through protections may impact their specific trading styles and cost profiles.
8. Wholesaler Oversight: For retail-facing firms, increase monitoring of wholesaler execution quality to ensure that the absence of Rule 611 does not lead to a degradation in price improvement.
9. Connectivity Cost Analysis: Analyze the potential impact of Rule 610(e) rescission on exchange access fees and whether this will lead to increased or decreased total cost of trading.
10. Compliance Training: Brief trading desks and legal departments on the distinction between ‘Price-Time Priority’ (which may remain at an exchange level) and ‘National Order Protection’ (which is being rescinded).

Open Questions / Watch Items

The most pressing unresolved issue is how the SEC will bridge the gap between the rescission of Rule 611 and the existing (or proposed) Best Execution rules. If Rule 611 is removed, the regulatory burden of proving ‘Best Ex’ increases exponentially. Will the Commission provide a new ‘Safe Harbor,’ or will broker-dealers be left to navigate a purely principles-based regime? The industry must monitor for supplemental guidance on what constitutes a ‘reasonable’ routing decision when a better price is displayed but ignored.

Another critical watch item is the impact on market transparency. Some critics argue that without the incentive of ‘protection,’ exchanges and traders may move even more volume into ‘dark’ pools or off-exchange venues, further fragmenting the price discovery process. The SEC’s release acknowledges this risk but posits that the increased competition among lit venues will actually improve the quality of displayed quotes. Whether this theory holds true in practice—or whether it leads to a ‘hollowing out’ of the public limit order book—remains to be seen.

Finally, the rescission of Rule 610(e) raises questions about the future of fair access. If the rules governing how participants connect to exchanges are loosened alongside trade-through protections, will we see the emergence of ‘tiered’ access models that favor larger players? Firms should closely monitor the responses from smaller exchanges, who are likely to argue that these changes unfairly benefit the ‘Big Three’ exchange families (NYSE, Nasdaq, Cboe) and large electronic market makers.

My Law Tampa publishes this regulatory update to provide a concise analysis of complex legal and compliance shifts in the financial services sector. Our focus is on translating administrative actions into actionable operational strategies for market participants and legal professionals.

The information provided in this memorandum is for informational purposes only and does not constitute legal advice. No attorney-client relationship is created by the publication or receipt of this memo. Readers should consult with qualified legal counsel regarding the specific application of these proposed rules to their business operations.

Source Materials

• Official publication: Release No. 2026-54
• Regulator archive: SEC memo archive
• Memo library: browse the full regulatory memo archive
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