US markets to expand to 23-hour weekday trading on Dec. 6

Starting December 6, 2026, US equity markets will operate 23 hours a day, five days a week. The one-hour break each evening, from 8 p.m. to 9 p.m. ET, is reserved for maintenance. Every other hour belongs to the traders.

The Securities and Exchange Commission approved the infrastructure changes needed to make this happen, and the agency has gone a step further: it’s openly exploring whether full 24/7 trading should come next.

How the new schedule works

The weekly cycle will kick off Sunday at 9 p.m. ET and run continuously, minus the nightly maintenance window, through Friday at 8 p.m. ET. A new “Night Session” covers the stretch from 9 p.m. to 4 a.m. ET each trading day, opening US equities to investors in Asia and Europe during their local business hours.

Nasdaq received accelerated approval for its extended-hours plan around April 2026. NYSE Arca is also among the major exchanges preparing for the launch.

The SEC approved amendments to the Securities Information Processors, or SIPs, on June 26, 2026. SIPs are the systems that consolidate and distribute real-time quote and trade data across exchanges.

Then, on June 28-29, the National Securities Clearing Corporation flipped the switch on its 24×5 clearing system. Clearing is the behind-the-curtain process that ensures when you buy a share, the seller actually delivers it and you actually pay.

Why now

Retail investors, who now represent a significant share of daily trading volume, have been vocal about wanting access outside the traditional 9:30 a.m. to 4 p.m. ET window. International investors have long had to set alarms or route orders through after-hours systems with thin liquidity and wide spreads to trade US stocks.

Several alternative trading systems and startup exchanges had already been offering overnight sessions for US equities, chipping away at the incumbents’ market share. Nasdaq and NYSE extending their own hours is partly a defensive move to recapture that flow.

What changes for investors and markets

In the early days, the Night Session will likely see thinner order books compared to regular hours, which means wider bid-ask spreads and potentially more volatile price swings on lower volume.

The NSCC’s continuous clearing should help reduce counterparty risk and encourage market makers to provide tighter quotes even during off-peak hours.

The SEC’s willingness to explore 24/7 trading would eliminate the “gap risk” that occurs between Friday’s close and Monday’s open, a period when geopolitical events, earnings surprises, or macroeconomic data can pile up with no way for stock prices to adjust in real time.

For now, December 6 marks the beginning of a phased transformation. The one-hour daily pause is a practical concession: systems need maintenance windows. Whether that pause eventually shrinks, or disappears entirely along with weekends, depends on how smoothly the next few months go.

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