Cboe EDGX Equities Expands Trading Hours

Overview

Effective December 6, 2026 (trade date December 7, 2026), Cboe EDGX Equities Exchange (EDGX) will expand trading hours as outlined below to follow a 23x5 schedule. Supporting market data changes will be made to BZX Equities Exchange (BZX), as outlined below.

Changes to the Cboe One U.S. Equities feed to accommodate the expanded trading hours are outlined in this notice. All times outlined in this notice are ET.

Trading Hours

Upon the effective date, EDGX trading hours will begin at 9:00 p.m. on Sundays and end at 8:00 p.m. on Fridays, as outlined below. Trades during the Overnight Trading Session occurring before midnight will be marked with the Trade Date of the following trading day.

Table 1. EDGX Trading Sessions
Session	Time	Order Handling
Queueing Period (Sunday-Thursday evening)	8:55 p.m. - 9:00 p.m.
Overnight Trading Session (Begins Sunday)	9:00 p.m. - 4:00 a.m.	Order instructions allowed are the same as for the current Early Trading Session. TimeInForce values accepted: IOC, FOK, DAY, GTC, GTX, and GTD. Pegged orders entered without a cap price are not permitted.
Pre-Market Trading Session	4:00 a.m. - 9:30 a.m.	Pegged orders entered without a cap price are not permitted.
Regular Trading Session (RTH)	9:30 a.m. - 4:00 p.m.	No changes from current behavior.
Post-Market Session	4:00 p.m. - 8:00 p.m.	Pegged orders entered without a cap price are not permitted.
Trading Pause	8:00 p.m. - 9:00 p.m.

Port Attributes

A new "Hold Early Orders Until" port attribute will be added to the FIX and BOE3 order entry protocols. If configured, the system will use the later of the start time specified or the start time of the TimeInForce value specified on the order. Start times may be set in 1/2 hour increments up to 9:00 a.m.

The "Early Trading Session Opt-Out" and "Hold Early to 7am" port attributes will be sunset on trade date December 7, 2026. Members using one of the two sunsetting port attributes who do not provide further instructions to the Cboe Trade Desk will have the new "Hold Early Orders Until" port attribute automatically added to their sessions with a configured start time that is commensurate to the legacy attribute being used.

To make port attribute changes, Members can use the Modify tab in the Logical Port Request tool in the Cboe Customer Web Portal.

Adjusted Application Restart Times

Beginning trade date November 2, 2026 on EDGX, restart times for all system processes will be moved as outlined below. Restart times for each individual system application may vary day to day due to operational need.


System Application (EDGX)	Current Start Time Range	New Start Time Range
System Application Startup (Sunday)	N/A. System starts Monday morning between 1:33-1:45 a.m.	~1:35-1:50 p.m. on Sunday
System Application Startup (Mon-Thurs)	1:33-1:45 a.m.	~8:10-8:22 p.m.

Beginning trade date November 2, 2026 on BZX, market data applications will restart at the new times outlined below to support regulatory halts disseminated during the Overnight Trading Session. Other applications, including order entry sessions and drop copies, will remain unchanged.


System Application (BZX)	Current Start Time Range	New Start Time Range
Market Data Application Startup (Sunday)	N/A. System starts Monday morning between 1:33-1:45 a.m.	~1:35-1:50 p.m. on Sunday
Market Data Application Startup (Mon-Thurs)	1:33-1:45 a.m.	~8:10-8:22 p.m.

Market Data Updates

The Time Reference message will be extended to BZX and EDGX effective trade date November 2, 2026 on the U.S. Equities Multicast PITCH, TCP PITCH, TOP, and Last Sale feeds.

The Time message will be extended from 6 bytes to 10 bytes with the addition of the Epoch Time field effective trade date November 2, 2026 on the U.S. Equities Multicast PITCH feed for BZX and EDGX only.

Effective trade date November 2, 2026, the Last Update Timestamp, Timestamp, and Transaction Time fields on the U.S. Equities Summary Depth Feed will be updated to contain the number of nanoseconds since epoch instead of the number of nanoseconds since midnight.

See the specifications linked below for more details. Cboe One feed changes are outlined in this notice.

Trade Data / Trade Detail Updates

Effective trade date November 2, 2026, the U.S. Equities Trade Data and Trade Detail files will include "Order Entry Date" as the first column.

Parallel Production Period

Beginning trade date November 9, 2026, the following test symbols will be supported in the EDGX Production environment for the Overnight Trading Session.

ZBZX
ZTST

Members are responsible for generating order and trade activity in these symbols in order to see test data on these symbols.

Testing Opportunities and Rollout Schedule

The testing opportunities and rollout schedule is as follows.


Milestone	Certification Trade Date	Production Trade Date
EDGX/BZX Application Restart Time Change, Trade Data/Trade Detail File Format Change, Time Message Expansion, and Time Reference Message Addition	08/31/26	11/02/26
Summary Depth Feed Last Update Timestamp, Timestamp, and Transaction Time Field Change	08/31/26	11/02/26
EDGX Parallel Production Period Begins with Test Symbols	N/A	11/09/26
Port Attribute Changes	10/05/26	12/07/26
Full 23x5 Trading Hours Effective	10/05/26	12/07/26

Additional Information

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Resources

For more information, please refer to the following:

Contact Information

Please contact the Cboe Trade Desk for support or with any questions.

Cboe Trade Desk: 913.815.7001 | [email protected]

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