The SEC held a public roundtable on September 17, 2026, to discuss preparations for expanded U.S. equity trading hours. The agenda covered overnight operations, resilience and the opportunities and challenges of expansion. Commissioner Hester Peirce’s remarks cited staff data showing extended-hours trading represented less than 1% of NMS-stock volume and was concentrated in a handful of stocks. SEC: Roundtable on Preparations for 24-Hour Trading SEC Commissioner Hester Peirce: Stock Around the Clock, September 17, 2026
Follow the evidence
Trace how the event could reach markets, then inspect a competing explanation.
Compare explanations
Switch lenses to see what each account explains—and what remains uncertain.
Expanded hours require brokers and infrastructure to support supervision and execution outside the core session.
Expanded hours require brokers and infrastructure to support supervision and execution outside the core session.
Low activity in the cited sample may not describe participation after venues expand schedules.
The session examined a market moving beyond core hours
The roundtable examined how U.S. equity markets could support overnight trading, how operations and resilience would work in a 24-hour environment, and what opportunities or challenges arise as hours expand. It brought market participants and regulators into a public discussion; it was not itself a final rule or a launch order for a universal 24-hour market. SEC: Roundtable on Preparations for 24-Hour Trading
Peirce described extended trading as taking shape in a 23-hour, five-day week. She cited SEC staff analysis that less than 1% of total trading in NMS stocks occurred in extended hours and activity was concentrated in a handful of stocks. Those figures describe the period and methodology in the underlying staff data, not a permanent ceiling on overnight volume. SEC Commissioner Hester Peirce: Stock Around the Clock, September 17, 2026
The commissioner pointed to infrastructure changes: NSCC moved clearing to a 24x5 model in June, and the SEC approved a longer operating schedule for the securities information processor, set to begin December 6, 2026. These are separate market-system milestones. They do not guarantee deep liquidity or identical trading conditions throughout all hours. SEC Commissioner Hester Peirce: Stock Around the Clock, September 17, 2026
Longer access can expose gaps in execution and oversight
Peirce raised questions about best execution when overnight liquidity is dispersed and spreads are wide. A broker’s duty does not disappear when fewer human staff are on shift, but execution quality may be harder to compare when venues, order types and available quotes differ. The SEC remarks frame this as a discussion, not a finding that brokers have breached obligations. SEC Commissioner Hester Peirce: Stock Around the Clock, September 17, 2026
Broker operations also depend on clearing, settlement, market-data distribution, corporate-action handling, surveillance and system maintenance. The SEC discussion asked how firms could supervise trading and risk overnight when automation does more of the work and regular maintenance windows are compressed. These are practical areas for readiness reviews, particularly where a retail interface implies uninterrupted access.
Issuers and investors face a timing question as well. Material news may arrive outside the traditional core session, while market participants still need reliable disclosure and time to interpret it. Peirce noted that EDGAR filings after 5:30 p.m. are typically processed the next business day and asked whether systems and issuer practices need to adapt. SEC Commissioner Hester Peirce: Stock Around the Clock, September 17, 2026
Separate operational milestones from a 24-hour policy decision
For brokers, map what happens when a customer places an order at 2 a.m.: which venue receives it, how a quote is evaluated, what happens if a primary data feed fails and who reviews an exception. Document spreads, execution outcomes, outages and complaints by session so overnight service can be assessed against evidence rather than interface design.
For clients, an “all-hours” toggle does not mean a stock is as liquid at every moment. Review available order types, spread disclosures, trading halts and the broker’s overnight-order terms. Consider whether a limit order or waiting for the core session fits the objective. These are general operational considerations, not personalised investment advice.
The SEC roundtable identifies design questions and records a discussion among market participants. The announced event and infrastructure milestones are confirmed; any broader policy outcome must be checked against subsequent SEC orders, exchange filings and official market-system notices. Longer hours are a process, not proof every safeguard has already been tested at full scale. SEC: Roundtable on Preparations for 24-Hour Trading SEC Commissioner Hester Peirce: Stock Around the Clock, September 17, 2026