SEC Proposes Historic Overhaul: The End of Regulation NMS Rules 611 and 610(e)

WASHINGTON, D.C. — June 11, 2026 — In a move that signals the most significant shift in U.S. equity market structure in over two decades, the Securities and Exchange Commission (SEC) announced today a formal proposal to rescind Rules 611 and 610(e) of Regulation NMS. The announcement, spearheaded by SEC Chairman Paul S. Atkins, marks a definitive break from the regulatory framework that has governed the National Market System since 2005.

The proposal, which aims to reduce market complexity and curtail the influence of rigid regulatory mandates, has sent shockwaves through Wall Street, prompting immediate debate among institutional investors, high-frequency trading firms, and retail brokerage platforms.

The Main Facts: What is Changing?

Regulation NMS, adopted in 2005, was designed to modernize the U.S. markets by promoting competition and ensuring that investors received the best possible prices. Central to this were two specific pillars:

• Rule 611 (The "Order Protection Rule"): This rule requires trading centers to establish, maintain, and enforce policies designed to prevent "trade-throughs"—transactions executed at a price inferior to a publicly displayed quote on another exchange.
• Rule 610(e) (The "Access Fee Cap"): This provision limits the fees that exchanges can charge for accessing their liquidity, intended to prevent excessive costs from distorting market pricing.

By proposing the rescission of these rules, the SEC is essentially moving toward a "market-driven" model. Under the proposal, the regulatory mandate to route orders to the best-displayed price would be removed, and the caps on access fees—which many critics argue have become a tool for exchange rent-seeking—would be eliminated. The Commission argues that these rules, while well-intentioned in 2005, have created a fragmented market landscape characterized by excessive complexity, "latency wars," and unintended technological bottlenecks.

Chronology: Two Decades of Market Evolution

To understand the weight of this decision, one must look back at the historical trajectory of Regulation NMS.

2005: The Birth of Reg NMS

Following the decimalization of the stock market in the early 2000s, the SEC introduced Regulation NMS to solve the problem of market fragmentation. The goal was to create a "National Market System" where all exchanges were interconnected. Rule 611 was the crown jewel of this effort, designed to ensure that retail and institutional orders were always filled at the best available price across the entire ecosystem.

2010–2015: The Rise of High-Frequency Trading (HFT)

As electronic trading took hold, critics began to observe that Rule 611 was being exploited. High-frequency traders utilized the "trade-through" protection to engage in complex strategies that relied on millisecond-level speed advantages. The "latency arbitrage" phenomenon emerged, leading many market participants to argue that Rule 611 was no longer protecting investors, but rather protecting the profits of the fastest participants.

2020–2025: Increasing Fragmentation

Over the last five years, the proliferation of off-exchange trading, dark pools, and retail-internalized order flow has led to a market where the "consolidated tape" often lags behind the actual execution of trades. Industry leaders, including major exchange operators and asset managers, have lobbied the SEC for years to address the "unintended consequences" of the 2005 framework.

2026: The Paradigm Shift

Today’s proposal represents the culmination of this growing frustration. Chairman Atkins has framed this as a return to "market-led efficiency," suggesting that the government should no longer mandate specific routing behaviors in a digital age that is vastly different from the era of floor-based trading.

Supporting Data and Economic Rationale

The SEC’s proposing release provides extensive data on the current state of the equity markets. Among the key metrics cited by the Commission are:

1. The Complexity Tax: The current regulatory overhead requires market participants to maintain thousands of lines of code to comply with order-routing logic, which the SEC estimates costs the industry billions annually in technological maintenance.
2. Liquidity Fragmentation: Despite the goal of a "unified" market, data shows that liquidity is more fragmented than ever, with a significant percentage of retail volume being internalized by wholesalers rather than interacting with public exchange limit orders.
3. The Access Fee Distortion: Analysis indicates that the current access fee caps, rather than lowering costs, have led to a "rebate" system where exchanges pay brokers to route orders to them, creating a conflict of interest that may not prioritize the investor’s best interest.

The SEC argues that rescinding these rules will allow for a more natural price discovery process. By removing the mandatory "trade-through" protection, the Commission believes that exchanges will be incentivized to compete on service quality, reliability, and innovative order types rather than simply relying on regulatory mandates to force order flow to their venues.

Official Responses: A Divided Industry

The reaction to the proposal has been swift and polarized, reflecting the divergent interests within the financial sector.

Chairman Paul S. Atkins’ Perspective

In his statement, Chairman Atkins was clear: "After two decades of Rule 611, it is high time that the Commission review its unintended consequences that have hindered—rather than enhanced—the long-term growth of our markets." He emphasized that the SEC is taking a "careful, deliberative approach" and explicitly invited public discourse to ensure that the transition away from these rules does not create systemic instability.

Institutional Investors

Many large asset managers have expressed cautious optimism. For years, institutional firms have complained about the "leakage" of information when executing large block trades. By removing the rigid requirements of Rule 611, they hope to regain more control over their order execution strategies, potentially reducing the ability of HFT firms to front-run their large orders.

Exchange Operators and HFT Firms

The response from exchanges has been mixed. Some major exchange operators, who have benefited from the predictable revenue streams provided by the current access fee structure, have signaled concerns regarding the potential for "race-to-the-bottom" pricing. Conversely, high-frequency trading firms are assessing how the lack of a "trade-through" rule will impact their ability to provide liquidity. Some firms fear that without the mandate, the market could lose its veneer of "best execution," leading to wider spreads and higher costs for retail investors.

Implications: The Road Ahead

The rescission of Rules 611 and 610(e) will not happen overnight. The SEC has initiated a 60-day public comment period, and the agency is expected to face significant pushback from retail advocacy groups who fear that removing price protection could leave smaller investors vulnerable.

1. Re-engineering Execution Algorithms

Broker-dealers will need to fundamentally rewrite their order-routing algorithms. If the "best price" rule is no longer enforced by law, brokers will need to develop sophisticated internal benchmarks for what constitutes "best execution" to meet their fiduciary duties to clients.

2. A Shift in Exchange Competition

With the removal of the access fee cap, exchanges will likely experiment with new pricing models. We may see a return to competitive bidding for order flow, which could lower transaction costs for some participants but potentially increase the cost of data and connectivity.

3. Impact on Market Volatility

A significant concern for regulators is whether the removal of these rules could lead to increased market volatility. If liquidity is no longer "protected" at the best price, there is a risk that orders could be executed at inferior prices during periods of extreme market stress. The SEC has signaled that it will be closely monitoring these risks and may implement "guardrail" measures to prevent such outcomes.

4. Regulatory Evolution

This proposal is a clear indication that the SEC is pivoting away from the "command-and-control" style of regulation that dominated the early 21st century. Whether this move leads to a more efficient, innovative market or one that is prone to greater inequality remains the defining question of the next decade of finance.

Conclusion

As the financial world digests the 2026 proposal, the consensus is clear: the U.S. equity market is on the brink of a new era. The rescission of Rules 611 and 610(e) represents a bold attempt to strip away layers of regulatory complexity that have defined the trading landscape for twenty years.

The next 60 days of public comment will be critical. The SEC faces the challenge of balancing the need for market efficiency with the necessity of investor protection. As Chairman Atkins stated, the Commission is looking to "avoid repeating the same mistakes that brought us here." Whether the market participants view this as a liberation from outdated constraints or a risky abandonment of investor safeguards will determine the final shape of the rule change.

Market participants, regulators, and academics are now entering a period of intense scrutiny. The outcome of this proposal will likely serve as the benchmark for future regulatory philosophy in the United States, proving whether a modern, decentralized market can truly self-regulate without the heavy hand of the National Market System.