Cboe BYX adopts Start Time order instruction for pre-market orders
The rule, filed Oct. 15, 2026 (Release No. 34-106744; File No. SR-CboeBYX-2026-039) becomes effective immediately and will be implemented Dec. 7, 2026, affecting all BYX users.
On October 15, 2026, Cboe BYX Exchange, Inc. filed a non-controversial proposed rule change with the Securities and Exchange Commission (Release No. 34-106744; File No. SR-CboeBYX-2026-039). The notice, published October 27, 2026 (FR Doc No. 2026-22133), announces immediate effectiveness of the filing.
The amendment revises Rule 11.1(a) to add a "Start Time" order instruction. Users may designate a start time in thirty-minute increments prior to the commencement of Regular Trading Hours; the earliest practical start time is 7:00 a.m. ET and the latest is 9:00 a.m. ET. The instruction is optional and mirrors the Start Time provision adopted by the affiliated Cboe EDGX Exchange.
Order-acceptance restrictions remain unchanged for the same categories of orders (BYX Post Only, ISOs, certain Market Orders, Minimum Quantity Orders with Regular Hours Only, RPI Orders, and orders with IOC or FOK time-in-force). Under the proposal, these restrictions apply before 7:00 a.m. or, if later, before the order's designated Start Time.
The Exchange plans to implement the Start Time instruction on December 7, 2026, in coordination with EDGX, to provide consistent order-handling functionality across Cboe-affiliated equities exchanges. The text of the proposed rule change is available on the SEC's website, the BYX website, and at the Exchange's principal office.
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