Marex Group plc美股招股说明书(2026-07-06版)

ETF Underlying SupplementTo Prospectus dated July6, 2026 andProspectus Supplement dated July6, 2026 Marex Group Limited Notes Linked to a Reference Asset Marex Group Limited from time to time may offer and sell certain senior unsecured debt obligations (the “Notes”) linked to a Reference Asset. The“Reference Asset” is the underlying measure by which we will determine the amount payable on the Notes, if any, and may be based on pricemovements in, performance of, or other events relating to one or more particular indices, index funds or other securities, currencies, interest rates,consumer prices, or commodities or commodity futures, or baskets comprised of any of those instruments or measures, or other instruments ormeasures, including the occurrence or nonoccurrence of any event or circumstance, or a combination thereof. This underlying supplement describescertain terms of the Notes linked to a Reference Asset that is an exchange traded fund or a trust that issues depositary receipts representing an interest inequity securities, bonds, commodities or any other assets held by such trust (each, a “Fund”). A Fund may track the performance of an index (ifapplicable, its “Underlying Index”), a basket of equity securities, or one or more types of bonds or other instruments or commodities, primarily by holdingsuch assets related to the foregoing. The Reference Asset may be a basket of Funds or a basket of instruments or measures that includes a Fund as oneof its components. We refer to any instrument or measure that comprises a basket as a “Basket Component,” and collectively as the “BasketComponents.” The Notes may also be linked to the worst performing of two or more Funds. The applicable free writing prospectus or pricing supplementwill specify the Reference Asset to which your Notes are linked as well as specific terms of the Notes. Notwithstanding anything to the contrary set forth in the accompanying prospectus supplement for Notes, SeriesA dated July6, 2026 (the “ProspectusSupplement”) and the accompanying base prospectus for senior debt securities dated July6, 2026 (the “Base Prospectus”), this underlying supplementdescribes additional terms of the Notes, certain risks related to the Funds, and some of the Funds to which the return on the Notes may be linked. You should read the applicable free writing prospectus or pricing supplement, this underlying supplement, the Prospectus Supplement and the BaseProspectus carefully before you invest in a particular issuance of the Notes. If the terms described in the applicable free writing prospectus or pricingsupplement are different from or inconsistent with those described herein, the terms described in the applicable free writing prospectus or pricingsupplement will govern the applicable Notes. The descriptions of Funds in this underlying supplement only apply to selected Funds to which the Notes may be linked. We do not guarantee that we willoffer the Notes linked to any of the Funds described herein. In addition, we may offer the Notes linked to one or more Funds that are not described herein.In such an event, we will describe such additional Fund or Funds in the applicable free writing prospectus or pricing supplement, or in another underlyingsupplement. An investment in the Notes involves certain risks. You should refer to “Risk Factors” beginning on page S-1 of this document and page S-1 ofthe Prospectus Supplement for risks related to an investment in the Notes. Neither the Securities and Exchange Commission (the “SEC”) nor any state securities commission has approved or disapproved of the Notes or passedupon the accuracy or the adequacy of this document, the Base Prospectus, the Prospectus Supplement or any free writing prospectus or pricingsupplement. Any representation to the contrary is a criminal offense. Unless otherwise specified in the applicable free writing prospectus or pricing supplement, the Notes will not be listed on a U.S. securities exchange. Application will be made for the Notes to be admitted to listing and trading on the Vienna Multilateral Trading Facility (“Vienna MTF”) of the Vienna StockExchange. The Vienna MTF is not a regulated market as defined by Directive 2014/65/EU (as amended, “MiFID II”). It is, however, a multilateral tradingfacility (MTF) for purposes of MiFID II. The Notes will be our direct, senior and unsecured obligations and will rank equally with all of our other existing and future senior unsecured The Notes are not bank deposits and are not insured or guaranteed by the Bermuda Deposit Insurance Corporation, the United Kingdom FinancialServices Compensation Scheme, the United States Federal Deposit Insurance Corporation or any other government or governmental or private agencyor deposit protection scheme in any jurisdiction. Table of Contents TABLE OF CONTENTS RISK FACTORSUSE OF PROCEEDS AND HEDGING REFERENCE SPONSORS AND FUNDSTHE GLOBAL X SILVER MINERS ETFTHE GLOBAL X URANIUM ETFTHE INVESCO QQQ TRU