UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 6-K

REPORT OF FOREIGN PRIVATE ISSUER

PURSUANT TO SECTION 13A-16 OR 15D-16

UNDER THE SECURITIES EXCHANGE ACT OF 1934

For the month of May 2025

Commission File Number: 001-42020

MAREX GROUP PLC

(Translation of registrant’s name into English)

155 Bishopsgate London EC2M 3TQ United Kingdom +44 2076 556000 140 East 45th Street, 10th Floor New York, New York 10017 (212) 618-2800

(Address of Principal Executive Offices)

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F.

Form 20-F ☒   Form 40-F ☐

EXPLANATORY NOTE

Departure of Director

On May 13, 2025, Roger Nagioff submitted his resignation as a member of the Board of Directors of Marex Group plc (the “Company”), effective immediately. Mr. Nagioff represented private equity investors and was a member of the Company’s Risk Committee and its Remuneration Committee.

Withdrawal of Annual General Meeting Proposal

On April 2, 2025, the Company published its Notice of the 2025 Annual General Meeting, which included the proposals to be voted on by the Company’s shareholders. As a result of Mr. Nagioff’s departure, the Company intends to withdraw the resolution proposing his re-election as a director at the forthcoming Annual General Meeting (“AGM”). The withdrawal of this resolution does not otherwise affect the validity of the documentation issued by the Company in connection with the AGM or any votes already submitted on other resolutions. The numbering of all other proposed resolutions at the AGM remains unchanged.

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

	Marex Group plc
Date: May 15, 2025	By:	/s/ Robert Irvin
		Robert Irvin
		Chief Financial Officer