U.S. SEC to Hold Public Roundtable on September 17 to Discuss Transition to Nearly 24/7 Trading in U.S. Securities Market
The U.S. Securities and Exchange Commission (SEC) will hold a public roundtable on September 17 to discuss preparations for the transition of the U.S. securities market to nearly 24/7 trading. Representatives from exchanges, brokerages, and market-making firms, including NYSE, Nasdaq, Robinhood, and Citadel Securities, will participate.
The meeting will take place at the SEC headquarters in Washington, D.C., from 10 AM to 4 PM ET and will be open to the public with a live webcast. Jamie Selway, Director of the SEC's Division of Trading and Markets, along with the Chair and Commissioners, will deliver opening remarks, followed by a presentation of market data related to extended trading hours by the Office of Data Analysis and Research.
The first discussion will focus on whether exchanges and brokerages are prepared to support a 24-hour market, including overnight market monitoring, closing price formation, clearing and settlement adjustments, investor protection measures, outstanding issues, and potential liquidity conditions under near-continuous trading.
The second discussion will address system resilience, covering Regulation SCI applicability, failover, capacity planning, market data continuity, shorter system maintenance windows, cybersecurity, and nighttime staffing. Continuous trading means that trading venues, brokerages, clearinghouses, and market data infrastructure can no longer rely on traditional overnight shutdown windows for batch processing and maintenance.
The third discussion will assess the impact of 24-hour trading on liquidity, capital formation, and the structure of participation between issuers and investors, and will discuss subsequent market structure regulatory issues. The SEC is also opening a public comment period for document number 4-913, allowing market participants, scholars, and individual investors to submit their opinions.
Currently, the U.S. stock market has not fully transitioned to 24-hour trading. Nasdaq previously received approval to extend daily trading hours to 23 hours, five days a week, and plans to start providing 23-hour market data from a securities information processor on December 6. The roundtable discussion on 24-hour trading is about whether trading, monitoring, clearing, and risk management can jointly support longer trading hours, not that the SEC has approved the stock market to be open 24/7.
In terms of market mechanisms, buyers include global investors, retail brokerages, market makers, and quantitative firms looking to continuously adjust U.S. stock risks across Asian, European, and U.S. time zones; sellers are financial infrastructure companies providing quotes, clearing, custody, market data, and financing capabilities. Funds will flow towards low-latency trading systems, nighttime compliance monitoring, cloud disaster recovery, market data distribution, clearing margins, and cross-time-zone operations; small and mid-cap stocks with weak liquidity, brokerages relying on retail order flow at night, and participants unable to bear the costs of 24/7 operations will face larger spreads, price impacts, and compliance pressures.
Source: Public Information
ABAB AI Insight
The SEC's roundtable meeting is set against the backdrop of the U.S. market gradually approaching the continuous trading model of the cryptocurrency market during extended trading hours. In 2025, NYSE Arca was approved to extend its daily trading hours from 16 hours; Nasdaq subsequently pushed for 23 hours, five days a week, and Cboe has also announced similar plans. Traditional exchanges have previously used overnight shutdowns for market data aggregation, corporate actions processing, margin calculations, system maintenance, and manual risk control; once these processes shift to continuous operation, it will not only change the opening times but also the backend settlement and operational rhythm of the U.S. securities market.
Capital flows will first concentrate on liquidity providers and infrastructure. Retail brokerages like Robinhood will gain longer customer trading hours, while NYSE and Nasdaq will have more matching and data distribution opportunities, and market makers like Citadel Securities will have to bear inventory and price discovery risks during the thinner liquidity of nighttime. Market makers will pass risks to traders through wider spreads, dynamic pricing, and hedging costs; clearinghouses will need to extend the frequency of risk monitoring and margin calculations. Increasing trading hours does not automatically increase the volume of funds; if new orders at night lack institutional counterparties, price quality may depend on the capital and risk control models of a few market makers.
Historical comparisons should look at the foreign exchange and cryptocurrency markets. Forex achieves nearly 24-hour trading through global banks, electronic brokers, and time zone relays, but liquidity is highly concentrated in London, New York, and major Asian time slots; cryptocurrency assets are truly open 24/7 but face deep declines, clearing waterfalls, and cross-platform price deviations during weekends and late nights. If U.S. stocks expand to 23×5, it will be closer to the continuous model of forex during working days rather than the 24/7 model of cryptocurrency; weekends remain the largest institutional boundary for U.S. securities settlement, corporate disclosures, and regulatory operations.
Essentially, this is a regulatory change. In the past, the trading hours of NYSE and Nasdaq were a form of market access rule, determining when benchmark prices were formed, when clearing occurred, and who could provide liquidity; now brokerages, tokenized stock platforms, and crypto derivatives continuously provide pre-market, after-hours, and even weekend risk prices, forcing regulators to redefine the boundaries of the "official market." The SEC's focus on monitoring, clearing, resilience, and investor protection indicates that the biggest obstacle to 24/7 trading is no longer the order interface, but who can maintain market order without a closing buffer in the event of abnormal quotes, market manipulation, system failures, or extreme volatility.
ABAB News · Cognitive Laws
- Extending trading hours first extends risk responsibility.
- The closer the market is to 24 hours, the more liquidity concentrates on a few nodes.
- The right to open will disappear, but the right to clear will not.