The U.S. Securities and Exchange Commission (SEC) will hold a public roundtable in September to discuss preparations for round-the-clock trading in American equities, as exchanges and brokers move to give global investors nearly continuous access to the world’s largest stock market.
The Sept. 17 roundtable will examine the operations and resilience needed to support overnight trading, as well as the opportunities and challenges arising from an expansion of market hours, the SEC said.
“We are moving towards a new day – and night – in the U.S. equity markets,” SEC Chairman Paul S. Atkins said.
“With the expansion to overnight trading, I’m excited at the prospect of U.S. equity markets aligning with those markets that already trade continuously and look forward to balancing round-the-clock trading with all-important investor and customer protections,” he added.
The discussion comes as major U.S. exchanges prepare to extend their trading sessions in response to growing demand from overseas and retail investors seeking to trade American stocks outside conventional market hours.
Nasdaq has said it plans to introduce a session running from 9 p.m. to 4 a.m. Eastern Time, creating a 23-hour trading day from Sunday evening through Friday.
The exchange currently expects the broader industry transition to begin in December 2026, subject to regulatory approval and readiness across market infrastructure providers.
NYSE Arca is also preparing to operate for 23 hours a day, five days a week, with trading expected to run from 9 p.m. through 8 p.m. Eastern Time, pending final implementation arrangements.
The shift would make U.S. equities more accessible to investors in Asia and Europe, who currently have to trade during overnight or early-morning hours in their local markets.
It would also allow investors to respond more quickly to corporate announcements, geopolitical events and economic data released outside the regular U.S. session.
However, expanding trading hours involves more than keeping exchange systems open for longer.
Clearing houses, broker-dealers, market-data providers and banks would need to operate across additional hours while maintaining sufficient staffing, liquidity, cybersecurity and risk controls.
Industry systems that depend on a clearly defined market close, including settlement, margin calculations and corporate-action processing, may also need to be redesigned.
SEC officials have previously said that several alternative trading systems already offer overnight trading and that investor demand, particularly from retail and non-U.S. participants, is driving momentum towards longer market hours.
The SEC roundtable signals that nearly continuous U.S. stock trading is shifting from an exchange-level experiment into a broader market-structure issue.
While exchanges can extend their own sessions, an effective 24-hour market requires the entire financial infrastructure to operate on a similar timetable.
A breakdown at a clearing firm, data provider or broker during thin overnight trading could affect investors even when an exchange’s own systems remain operational.
Liquidity is likely to be one of the central concerns. Trading volumes during overnight sessions may initially be concentrated in the largest technology companies, exchange-traded funds and other heavily traded securities.
Smaller stocks could face wider bid-ask spreads and sharper price moves, increasing execution risks for retail investors.