Overview

CTA/UTP, NYSE Arca, Cboe EDGX, MEMX, and 24X have confirmed readiness to support 23×5 trading hours. Beginning December 6, 2026 (for the December 7, 2026, trading day), these venues will introduce a new Overnight Trading Session, extending the U.S. equity trading week to approximately 23 hours per day, five days per week.

The CTA/UTP SIPs will operate from 9:00 p.m. ET Sunday through 8:00 p.m. ET Friday, with a nightly maintenance pause Monday-Thursday from 8:00 p.m. to 9:00 p.m. ET. The gap from Friday 8:00 p.m. ET to Sunday 9:00 p.m. ET is the weekend market closure, not a nightly maintenance pause.

Trading Schedule

Pre-market (Extended Early Hours)* 9:00 p.m.-4:00 a.m. (overnight segment)
4:00 a.m.-9:30 a.m. (morning segment)		 Processed as pre-market; both segments attributed to the next trading dayId
Regular 9:30 a.m.-4:00 p.m. Processed as regular trading hours
After-market (Late Hours) 4:00 p.m.-8:00 p.m. Processed as after-market
Maintenance pause (Mon-Thu nights) 8:00 p.m.-9:00 p.m. SIP unavailable; no real-time dissemination
Weekend closure Fri 8:00 p.m.-Sun 9:00 p.m. SIP unavailable; no real-time dissemination (not a nightly pause)

* For dxFeed consumers, pre-market is a single logical session spanning 9:00 p.m.–9:30 a.m. ET, consisting of the overnight and morning segments. Both segments are attributed to the following trading dayId for session attribution and daily statistics purposes.

Cboe EDGX and Cboe One

Parallel Production Period

Beginning the trade date of November 9, 2026, the following test symbols are supported in the EDGX production environment for the Overnight Trading Session. These test symbols will also appear on the Cboe One U.S. Equities feed:

  • ZBZX
  • ZTST

dxFeed plans to disseminate these symbols through its production endpoints to all consumers of the affected feeds.

MEMX

MEMX Equities does not plan to make test symbols available in production for the Overnight Session before the December 6, 2026, go-live date. MEMX also does not participate in Customer Weekend Tests.

Additional Information