SEC Approves Nasdaq Rule Change to Extend Trading to 23 Hours a Day
SEC approved a Nasdaq rule change to extend the trading hours for National Market System stocks and Exchange-Traded Products from 16 hours a day to 23 hours a day, five days a week (23/5).
According to the Notice, published in the Federal Register, Nasdaq will consolidate its existing trading hours into a single "Day Session" and introduce a new "Night Session," separated by a daily one-hour trading pause.
Previously, Nasdaq operated for 16 hours a day, five days a week, and completely closed overnight between 8:00 p.m. and 4:00 a.m. ET, as well as throughout the weekend. Under the new rule, Nasdaq will operate utilizing two primary sessions:
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The "Day" Session (4:00 a.m. to 8:00 p.m. ET): This session combines the current Pre-Market, Regular Market, and Post-Market hours into a single defined session. There are no substantive changes to how trading operates during these hours. All existing requirements, order types, and processes (including the Opening and Closing Crosses) remain the same.
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The "Night" Session (9:00 p.m. to 4:00 a.m. ET): This is a new trading session. The trading week will officially begin on Sunday night at 9:00 p.m. ET and conclude on Friday at 8:00 p.m. ET.
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Daily Trading Pause (8:00 p.m. to 9:00 p.m. ET): Trading will pause for one hour each weekday evening. All outstanding orders will be canceled at 8:00 p.m. ET. This pause allows Nasdaq to conduct system maintenance, process corporate actions (like stock splits or dividends), and shift operations to the distinct trading system instance used for the Night Session.
Because the Night Session operates during periods of lower liquidity and higher potential volatility, the exchange restricts functionality during the Night session compared to regular hours. The exchange restricted Night session trading to limit orders, explicitly prohibiting unpriced orders, pegged orders, and certain specialized order types. Market participants are required to use specifically designated ports to connect to the distinct trading system that operates the Night session. The exchange applied its clearly erroneous execution rules and Limit Order Protection mechanisms during the Night session. Members are required to provide customers with enhanced risk disclosures highlighting the specific dangers of overnight trading, including limited liquidity and higher volatility. The exchange conditioned the commencement of Night session operations on the readiness of the Securities Information Processor to handle overnight quotation and transaction data.
The exchange also updated various rulebook definitions, including Business Day and Extended Hours, to conform to the new 23-hour trading schedule.
The SEC approved the rule change on an accelerated basis on April 10, 2026, though the exchange delayed the launch of the Night session until the Securities Information Processor becomes operational for overnight hours.