2026-18537NoticeWallet

MEMX updates post-halt trading resumption rule

Published Date: 9/11/2026

Notice

Summary

No summary available.

Analyzed Economic Effects

3 provisions identified: 2 benefits, 0 costs, 1 mixed.

Keep 4 a.m. Restart After Level 3 Halt

If the S&P 500 drops 20% (a Level 3 Market Decline), MEMX will keep trading halted until 4:00 a.m. ET on the following trading day. This rule will remain in place even after the Exchange starts 23/5 trading (including an Overnight Session beginning December 6, 2026).

No Overnight Trading Day-of-Level 3 Halt

On any day a Level 3 Market Decline (20% S&P 500 drop) occurs, MEMX will not open its Overnight Trading Session (9:00 p.m. to 4:00 a.m.) that same calendar day and will instead resume trading at 4:00 a.m. ET the next trading day. This preserves the current practice of not offering overnight trading on the day of a Level 3 halt.

Same Resumption Time Across Markets

MEMX and the other U.S. equity exchanges and FINRA intend to keep a harmonized resumption time of on or after 4:00 a.m. ET following a Level 3 halt. That coordination is meant to avoid confusion and ensure consistent market behavior across venues when a Level 3 Market Decline occurs.

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Key Dates

Published Date
Effective Date
9/11/2026
9/27/2026

Department and Agencies

Department
Independent Agency
Agency
Securities and Exchange Commission
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