Will QUODD Support 23/5 US Markets Extended Hours?
Last updated: October 16, 2026
What is 23/5 trading?
23/5 trading allows eligible U.S.-listed equities and ETFs to trade 23 hours a day, five days a week. Nasdaq plans to introduce a new overnight trading session beginning December 6, 2026, extending trading availability beyond existing market hours.
When will extended trading hours begin?
Nasdaq is scheduled to begin 23/5 trading on December 6, 2026, subject to industry readiness. QUODD will support the extended sessions as participating U.S. exchanges begin offering 23/5 trading.
What are the new trading hours?
The new overnight session will operate from 9:00 PM to 4:00 AM Eastern Time (ET), with existing trading sessions remaining unchanged.
Trading Session | Hours (ET) |
|---|---|
Overnight (New) | 9:00 PM – 4:00 AM |
Pre-Market | 4:00 AM – 9:30 AM |
Regular Market | 9:30 AM – 4:00 PM |
After-Hours | 4:00 PM – 8:00 PM |
Trading Pause | 8:00 PM – 9:00 PM |
The trading week will begin Sunday at 9:00 PM ET and conclude Friday at 8:00 PM ET.
Will QUODD support 23/5 trading?
Yes. QUODD will support the new overnight trading sessions beginning December 6, 2026, in alignment with participating U.S. exchanges.
The new overnight session will follow the same API behavior as the existing Pre-Market session, using the current ExtendedHours fields.
Which QUODD APIs will support 23/5 trading?
The following APIs will support the extended trading session:
GlobalQuotes
GlobalRealTime
NasdaqLastSale
SuperQuotes (when using any of the above as underlying sources)
Will any API changes be required?
No. QUODD will maintain full backward compatibility, with no changes to existing API signatures or request parameters.
The current extended-hours behavior will remain consistent, with the primary difference being the additional hours during which pricing data may update.
How will overnight pricing be reflected in the APIs?
Endpoints containing ExtendedQuote or ExtendedQuotes will continue updating during the new overnight session.
The following fields will support updates during the extended session:
Extended-hours data: ExtendedHoursDate, ExtendedHoursTime, ExtendedHoursType, ExtendedHoursPrice, ExtendedHoursChange, ExtendedHoursPercentChange
Bid/Ask data: Bid, BidSize, BidDate, BidTime, Ask, AskSize, AskDate, AskTime
Additional fields: TradingHalted, Volume, VolumeDate
Updates will depend on the availability of market activity and incoming data.
Will historical intraday chart data include overnight trading?
Yes. The GetChartBars endpoint will support the full 23/5 trading session when the IncludeExtended parameter is set to True. This allows clients to retrieve intraday bars that include the new overnight trading session.
Will regular market hours or existing pricing behavior change?
No changes to existing QUODD API behavior are expected beyond the expanded hours of data availability. The regular U.S. trading session will remain 9:30 AM to 4:00 PM ET, with extended-hours pricing continuing to follow the existing methodology.
How will trade dates be handled during overnight trading?
According to Nasdaq, trades executed between 9:00 PM and midnight ET will be assigned the following trading day's trade date. Trades executed between midnight and 8:00 PM ET will use the current trading date.
Settlement processing will continue to be based on the assigned trade date.
Where can I find additional information?
For more details about the exchange rollout, trading hours, and market structure changes, please refer to Nasdaq's official resources: