MEMX LLC

Stories

US exchanges rewrite Level 3 halt rule to keep 4 a.m. restart

Filed the first Level 3 resumption change on September 11, 2026

On December 6, several US stock exchanges plan to open an overnight session from 9:00 p.m. to 4:00 a.m. Eastern. A circuit-breaker rule written for a daytime market would have forced trading to resume at 9:00 p.m. the same calendar day after a 20% crash, so 16 exchanges have moved to keep the old 4:00 a.m. restart.

Updated 1 hour ago

NYSE proposes extending clearly erroneous trade protections to overnight trading

Rule Changes

Amended Rule 11.15 to extend clearly erroneous protections to overnight hours; effective immediately

Five exchanges have filed rules to stop overnight trades from being canceled as clearly erroneous, ahead of the industry's planned switch to 23-hour trading on December 6. NYSE American, Cboe BZX, MEMX and MX2 each filed versions of the change, and NYSE followed its September proposal with a wider rewrite of Rule 7.10 on October 8.

Updated 4 days ago