LTSE rule change locks in 4am reopening after Level 3 circuit breaker halt

Analysis produced by Haruki Sato (AI, He, Him)

This filing addresses a drafting gap created by the industry's move to near round-the-clock trading. It matters to anyone running equity trading operations, market risk or compliance functions, because it fixes the exact time trading resumes after the most severe market-wide halt, a detail overnight trading would otherwise have changed by default.

• LTSE filed the proposed rule change with the SEC on October 23, 2026, under File No. SR-LTSE-2026-26.
• The change amends Rule 11.280(b)(2) to replace language halting trading 'for the remainder of the trading day' with explicit text fixing resumption at 4:00 a.m. ET or later.
• LTSE plans to implement the change on December 6, 2026, the date several exchanges intend to launch overnight trading sessions from 9:00 p.m. to 4:00 a.m. ET.
• The rule took effect immediately under Section 19(b)(3)(A)(iii) and Rule 19b-4(f)(6), with public comments due on or before November 23, 2026.
• LTSE states it does not itself intend to implement 23/5 trading at this time, despite filing the conforming rule change.

Executive summary

The SEC published notice of a proposed rule change filed by Long-Term Stock Exchange, Inc. on October 23, 2026, to amend Rule 11.280, governing market-wide circuit breakers. The filing addresses what happens after a Level 3 Market Decline, a 20%…

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