Cboe BZX Extends Clearly Erroneous Execution Protections to Overnight Hours

On September 24, 2026, Cboe BZX Exchange, Inc. filed a proposed rule change with the Securities and Exchange Commission that is effective immediately, as noted in the notice published on October 7, 2026 (FR Doc No. 2026-20797, Release No. 34-106622; File No. SR-CboeBZX-2026-079). The filing amends Rule 11.17, which governs Clearly Erroneous Executions (CEE).

The amendment responds to the Commission's August 5, 2026 approval of Overnight Protected Bands under the Limit Up-Limit Down (LULD) Plan for 23/5 Trading. By adding "Overnight Protected Hours" (9:00 p.m. ET through 4:00 a.m. ET) to the definition of "LULD Protected Hours," the Exchange seeks to extend the LULD-based restriction on CEE reviews to the overnight trading session.

Key changes include replacing the phrase "Regular Trading Hours" with "LULD Protected Hours" in Rule 11.17(c)(1), redefining "LULD Price Bands" and adding "Overnight Price Bands" (temporary static bands 20% above and below two reference points), and updating the percentage-parameter reference to incorporate the "Overnight Percentage Parameter" for trades executed during overnight protected hours. The proposal also revises Rule 11.17(c)(2) and related subsections to cover transactions in NMS stocks not subject to the LULD Plan during overnight hours, applying the same numerical guidelines used for early-trading, pre-opening, and after-hours sessions.

In addition to these substantive revisions, the Exchange makes non-substantive language updates throughout the rule, such as substituting "LULD Plan" for its longer description. The notice invites comments from interested persons, with the filing already in effect.