# Federal Register #SR-CboeBYX-2026-034

Cboe BYX proposal to clarify trading resumption after a Level 3 market-wide circuit breaker

**Buyer:** Securities and Exchange Commission
**Posted:** October 08, 2026
**Respond By:** October 29, 2026
**Identifier:** SR-CboeBYX-2026-034

The Securities and Exchange Commission notice concerns a proposed Cboe BYX Exchange, Inc. rule clarification, not a procurement opportunity.
- **Government entity:** U.S. Securities and Exchange Commission (SEC).
- **Company named:** Cboe BYX Exchange, Inc., the exchange proposing the rule change.
- **Proposal:** Amend BYX Rule 11.29(b)(2) to clarify that all stocks remain halted after a Level 3 market-wide circuit breaker until 4:00 a.m. ET or later on the following trading day.
- **Purpose:** Preserve the existing cooling-off period and coordinated market-wide resumption practice as some exchanges expand trading hours.
- **Procurement items:** No products, services, quantities, part numbers, or OEMs are identified. The notice invites public comments.

### Description

Cboe BYX Exchange, Inc. proposes to amend Rule 11.29(b)(2), which governs resumption of trading after a Level 3 market-wide circuit breaker halt. The amendment would specify that trading in all stocks remains halted until 4:00 a.m. ET or later on the following trading day, in connection with the industry's planned expansion to 23-hour-per-day, five-day-per-week trading. The notice states that the change is intended to preserve the existing resumption timing and cooling-off period, rather than make substantive changes to the market-wide circuit breaker mechanism. The Securities and Exchange Commission published the notice to solicit comments on the proposed rule change.

[View original listing](https://www.federalregister.gov/documents/2026/10/08/2026-20600/self-regulatory-organizations-cboe-byx-exchange-inc-notice-of-filing-and-immediate-effectiveness-of)