Nasdaq says it will trade US equities for 23 hours a day, five days a week, from Sunday the 6th of December. The exchange gives that as a firm date in an explainer published on Friday, though some supporting rules still await SEC approval.
The trading day is currently 16 hours: pre-market from 4am to 9:30am ET, regular trading until 4pm, then post-market until 8pm. The new week opens at 9pm ET on Sunday and closes at 8pm ET on Friday, with a one-hour pause from 8pm to 9pm ET each weekday for clearing, settlement and reference data.
Law firms Skadden and Jones Day describe two sessions: a Night Session from 9pm to 4am ET and a Day Session from 4am to 8pm ET. UK times below are our conversions of Nasdaq’s ET hours at the five-hour winter gap that applies from the 6th of December. The gap is four hours this week and widens to five when US clocks go back on Sunday.
| Session | ET | UK (GMT) |
|---|---|---|
| Night Session | 21:00-04:00 | 02:00-09:00 |
| Day Session | 04:00-20:00 | 09:00-01:00 (next day) |
| Regular hours, with crosses | 09:30-16:00 | 14:30-21:00 |
| Daily pause | 20:00-21:00 | 01:00-02:00 (next day) |
For UK traders, the overnight session fills the small hours and morning before the US pre-market. The opening and closing crosses, the auctions that set the 9:30am open and the 4pm close, are kept, and US market holidays are still observed.
Chuck Mack, Nasdaq’s Senior Vice President of North American Markets, framed the change around investors outside US time zones.
23/5 trading reflects a simple reality: global investor behavior is changing, and investors increasingly expect access to U.S. markets that aligns with their own time zones and information cycles,
Chuck Mack, Nasdaq
Access is narrower than the hours suggest. Skadden and Jones Day say only US broker-dealers that are exchange members can trade overnight, so retail investors must go through one. Jones Day also reports there is no opening auction in the overnight session, and that the SEC’s approval of it is conditioned on temporary 20% price bands. The SEC approved Nasdaq’s proposal on the 10th of April.
Nasdaq says most liquidity is still expected during traditional US hours. Panellists at an SEC roundtable, relayed by Jones Day, said overnight volume peaks from 8pm to 9pm ET and is low for the rest of the night.
Nasdaq says its regulatory proposals are still proceeding through the approval process, and a fee clarification for the overnight session is among the rules awaiting SEC approval. Which UK platforms will offer the session, and on what terms, is not yet confirmed.