Nasdaq amends rule on post-circuit-breaker trading as it adds night session

On September 25, 2026, The Nasdaq Stock Market LLC filed a proposed rule change with the Securities and Exchange Commission (File No. SR-NASDAQ-2026-080; Release No. 34-106586). The filing, published in the Federal Register on October 8, 2026 (Vol. 91, No. 194, pp. 64439-64442), proposes to amend Equity 4, Rule 4121(b)(ii) concerning the resumption of trading after a Level 3 market-wide circuit breaker (MWCB) halt. The Exchange designated the proposal as non-controversial under Section 19(b)(3)(A)(iii) and the amendment is effective immediately upon filing.

The amendment's purpose is to preserve the Exchange's current 4:00 a.m. Eastern Time (ET) or later resumption time following a Level 3 Market Decline, even as the Exchange expands its trading schedule to 23 hours per day, five days per week ("23-5 Trading"). The change does not alter the MWCB mechanism itself; it merely ensures that the resumption time remains consistent with coordinated market practice when the Night Session is in effect.

Under 23-5 Trading, the Night Session will run from 9:00 p.m. ET to 4:00 a.m. ET, and is expected to become operative on or about December 6, 2026. The proposed rule deletes the language that trading would halt "for the remainder of the trading day" after a Level 3 decline and replaces it with language stating that trading will not resume until 4:00 a.m. ET or later on the following trading day.

The Exchange will coordinate the operative date with other self-regulatory organizations and the Commission, and will notify customers through a Trader Alert. The statutory basis for the filing is Section 19(b)(1) of the Securities Exchange Act of 1934 and Rule 19b-4 thereunder, and comments are being solicited from interested persons.