Americas Reg Desk

Wednesday, 2026-10-28 · covering the last 24h

United States

SEC lets Cboe Clear U.S. margin count toward broker-dealer reserve computations. A Section 36(a)(1) exemptive order permits broker-dealers that are clearing members of Cboe Clear U.S. (CCUS) to include customer binary-options margin held at CCUS in the Rule 15c3-3a reserve-formula debit — a treatment previously confined to margin held at the OCC — a follow-on to CCUS's temporary clearing-agency registration reported yesterday. The relief is conditioned on CCUS staying a registered clearing agency, segregating customer from proprietary margin, and bringing any future change to its margin methodology back to the SEC for review. Federal Register order

MEMX extends clearly-erroneous-execution review to overnight trading. Rule filing SR-MEMX-2026-33 reverses MEMX's earlier carve-out and applies LULD-based review of clearly erroneous executions to its Overnight Trading Session (9pm–4am ET), replacing "Regular Trading Hours" with a new "LULD Protected Hours" definition now that the SEC has approved Overnight Price Bands under the LULD Plan. Effective immediately on filing, it is expected to be mirrored by other exchanges and FINRA ahead of industry-wide 24-hour trading's 6 December launch. Federal Register filing

Otherwise routine: the day's other Federal Register items were SRO fee-schedule housekeeping and an OCC clearing-member-standards approval; the CFTC filed no new rulemaking and FINRA's notices are unchanged since yesterday.

Canada

Nothing new from CIRO, the CSA, TMX, the CDCC or the Bank of Canada's rulemaking channels since yesterday.

Latin America

A quiet window across Brazil, Mexico, Argentina and Chile; nothing new from the CVM, B3, Banxico, the BCRA or Chile's CMF.

Informational only — summaries of public regulatory and central bank sources; not advice.