Marex Group (MRX) JRJ-affiliated investors report 0% beneficial stake in 13G/A

Rhea-AI Filing Summary

Marex Group plc received an amended Schedule 13G filing from JRJ Investor 1 LP, Amphitryon Limited (in liquidation), JRJ Group Limited, Sir Jeremy Isaacs and Mr. Roger Nagioff regarding Marex common stock, par value $0.001551 per share. The filing states that Amphitryon Limited directly holds 0 shares of Marex and that JRJ Investor 1 LP, JRJ Group Limited, Sir Jeremy Isaacs and Mr. Roger Nagioff may previously have been deemed to share beneficial ownership of shares once held by Amphitryon Limited.

The group now reports 0 shares with 0% of the class, and no sole or shared voting or dispositive power over Marex common stock. The filing confirms they are owners of 5 percent or less of this class of securities.

Key Figures

Par value per share: $0.001551 per share Beneficially owned shares: 0 shares Percent of class owned: 0% +3 more

6 metrics

Par value per share $0.001551 per share Par value of Marex Group plc common stock

Beneficially owned shares 0 shares Amphitryon Limited directly held 0 Shares as of the reporting date

Percent of class owned 0% Group reports 0% beneficial ownership and 5 percent or less of the class

Sole voting power 0 Sole power to vote or direct the vote over Marex common stock

Shared voting power 0 Shared power to vote or direct the vote over Marex common stock

Sole dispositive power 0 Sole power to dispose or direct disposition of Marex common stock

Key Terms

beneficial ownership, Schedule 13G, sole voting power, dispositive power, +1 more

5 terms

beneficial ownership financial

"they may have be deemed to have or share beneficial ownership of the"

Beneficial ownership means the person or entity that actually enjoys the benefits of owning shares or other assets — such as receiving dividends, voting rights, or price gains — even if the legal title is held in another name. For investors it matters because knowing who truly controls and profits from a company reveals who can influence decisions, exposes potential conflicts of interest or hidden concentration of power, and affects transparency and risk in the stock.

Schedule 13G regulatory

"Ownership of 5 percent or less of a class on Schedule 13G"

A Schedule 13G is a formal document that investors file with the government when they acquire a large ownership stake in a company, usually for investment purposes rather than control. It helps keep the public informed about who owns significant parts of a company's shares, which can influence how the company is managed and how investors make decisions. Filing this schedule is important for transparency and understanding the ownership landscape of publicly traded companies.

sole voting power financial

"Sole Voting Power 0.00 6 | Shared Voting Power 0.00"

Sole voting power is the exclusive right to cast votes attached to a shareholder’s stock without needing approval from anyone else. Like holding the only remote control for a TV, it lets that holder decide corporate matters such as board members, mergers, and policy changes, making it important to investors because it concentrates control and can strongly influence a company’s strategy and the value of its shares.

dispositive power financial

"Sole Dispositive Power 0.00 8 | Shared Dispositive Power 0.00"

Dispositive power is the authority to decide the final outcome of an asset, legal claim, contract, or corporate action — in effect the power to dispose of or resolve something. For investors it matters because whoever holds that authority can determine who gets paid, who controls an asset or vote, and how risks and returns are allocated; think of it like holding the key that lets you lock in the winner or loser in a deal.

percent of class financial

"Percent of class (c) | Number of shares as to which the person has"

Percent of class is the portion of a specific category of securities—such as a company’s common shares, preferred shares, or a bond series—that takes part in or approves a corporate action (vote, consent, tender, etc.). Investors watch this number because it reveals how much support or opposition exists within that particular shareholder group; like counting how many members of a club back a proposal, it can determine whether a plan passes or how influence is distributed.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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Available on EDGAR 08/10/2026 - 10:31 AM Accepted by SEC EDGAR 08/10/2026 - 10:31 AM Learn about SEC filing dates

FAQ

What change does the Schedule 13G/A report for Marex Group plc (MRX)?

The Schedule 13G/A reports that JRJ Investor 1 LP, Amphitryon Limited, JRJ Group Limited, Sir Jeremy Isaacs and Roger Nagioff now report 0 shares and 0% beneficial ownership of Marex Group plc common stock, indicating ownership of 5 percent or less of the class.

Who are the reporting persons in the Marex Group plc (MRX) Schedule 13G/A?

The reporting persons are JRJ Investor 1 LP, Amphitryon Limited (in liquidation), JRJ Group Limited, Sir Jeremy Isaacs, and Mr. Roger Nagioff, all associated through ownership and control relationships described in the filing.

How many Marex Group plc (MRX) shares are beneficially owned by the JRJ group?

The filing states that Amphitryon Limited directly holds 0 shares of Marex Group plc, with the JRJ-related entities and individuals also reporting 0 shares beneficially owned and no sole or shared voting or dispositive power over the common stock.

What percentage of Marex Group plc (MRX) does the JRJ group report owning?

The reporting group discloses beneficial ownership of 0% of Marex Group plc’s common stock. Item 5 specifies that they are owners of 5 percent or less of the class of these securities.

What security is covered in this Marex Group plc (MRX) Schedule 13G/A?

The filing covers Marex Group plc Common Stock with a par value of $0.001551 per share, identified by CUSIP G5S37H101, and reports the current beneficial ownership status of the JRJ-related entities and individuals.

Where are the JRJ reporting entities for Marex Group plc (MRX) organized?

JRJ Investor 1 LP, Amphitryon Limited and JRJ Group Limited are each organized under the laws of Jersey, while Sir Jeremy Isaacs and Mr. Roger Nagioff are identified as British citizens, all sharing a business address in St. Helier, Jersey.

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. 2)

Marex Group plc

(Name of Issuer)

Common Stock, par value $0.001551 per share

(Title of Class of Securities)

G5S37H101

(CUSIP Number)

06/30/2026

(Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

Rule 13d-1(b)

Rule 13d-1(c)

Rule 13d-1(d)

schemaVersion:

SCHEDULE 13G

CUSIP Number(s): G5S37H101

1

Names of Reporting Persons

JRJ Investor 1 LP

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

JERSEY

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 0.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

0.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

0 %

12

Type of Reporting Person (See Instructions)

PN

Comment for Type of Reporting Person: Amphitryon Limited was the record holder of the shares previously reported herein. JRJ Investor 1 LP is the indirect sole shareholder of Amphitryon Ltd. JRJ Investor 1 LP is indirectly controlled by JRJ Group Limited, which is controlled by Sir Jeremy Isaacs and Mr. Roger Nagioff. As such, they may have be deemed to have or share beneficial ownership of the ordinary shares previously held directly by Amphitryon Limited.

SCHEDULE 13G

CUSIP Number(s): G5S37H101

1

Names of Reporting Persons

Amphitryon Limited (in liquidation)

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

JERSEY

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 0.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

0.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

0 %

12

Type of Reporting Person (See Instructions)

CO

Comment for Type of Reporting Person: Amphitryon Limited was the record holder of the shares previously reported herein. JRJ Investor 1 LP is the indirect sole shareholder of Amphitryon Ltd. JRJ Investor 1 LP is indirectly controlled by JRJ Group Limited, which is controlled by Sir Jeremy Isaacs and Mr. Roger Nagioff. As such, they may have be deemed to have or share beneficial ownership of the ordinary shares previously held directly by Amphitryon Limited.

SCHEDULE 13G

CUSIP Number(s): G5S37H101

1

Names of Reporting Persons

JRJ Group Limited

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

JERSEY

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 0.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

0.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

0 %

12

Type of Reporting Person (See Instructions)

CO

Comment for Type of Reporting Person: Amphitryon Limited was the record holder of the shares previously reported herein. JRJ Investor 1 LP is the indirect sole shareholder of Amphitryon Ltd. JRJ Investor 1 LP is indirectly controlled by JRJ Group Limited, which is controlled by Sir Jeremy Isaacs and Mr. Roger Nagioff. As such, they may have be deemed to have or share beneficial ownership of the ordinary shares previously held directly by Amphitryon Limited.

SCHEDULE 13G

CUSIP Number(s): G5S37H101

1

Names of Reporting Persons

Sir Jeremy Isaacs

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

UNITED KINGDOM

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 0.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

0.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

0 %

12

Type of Reporting Person (See Instructions)

IN

Comment for Type of Reporting Person: Amphitryon Limited was the record holder of the shares previously reported herein. JRJ Investor 1 LP is the indirect sole shareholder of Amphitryon Ltd. JRJ Investor 1 LP is indirectly controlled by JRJ Group Limited, which is controlled by Sir Jeremy Isaacs and Mr. Roger Nagioff. As such, they may have be deemed to have or share beneficial ownership of the ordinary shares previously held directly by Amphitryon Limited.

SCHEDULE 13G

CUSIP Number(s): G5S37H101

1

Names of Reporting Persons

Mr. Roger Nagioff

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

UNITED KINGDOM

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 0.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

0.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

0 %

12

Type of Reporting Person (See Instructions)

IN

Comment for Type of Reporting Person: Amphitryon Limited was the record holder of the shares previously reported herein. JRJ Investor 1 LP is the indirect sole shareholder of Amphitryon Ltd. JRJ Investor 1 LP is indirectly controlled by JRJ Group Limited, which is controlled by Sir Jeremy Isaacs and Mr. Roger Nagioff. As such, they may have be deemed to have or share beneficial ownership of the ordinary shares previously held directly by Amphitryon Limited.

SCHEDULE 13G

Item 1.
(a)	Name of issuer: Marex Group plc
(b)	Address of issuer's principal executive offices: 155 Bishopsgate, London, United Kingdom, EC2M 3TQ
Item 2.
(a)	Name of person filing:
(b)	Address or principal business office or, if none, residence:
(c)	Citizenship: (i) JRJ Investor 1 LP ("JRJ Investor 1") 44 Esplanade, St. Helier, JE4 9WG, Jersey Citizenship: Limited partnership organized under the laws of Jersey (ii) Amphitryon Limited (in liquidation) ("Amphitryon Ltd.") 44 Esplanade, St. Helier, JE4 9WG, Jersey Citizenship: Company organized under the laws of Jersey (iii) JRJ Group Limited ("JRJ Group") 44 Esplanade, St. Helier, JE4 9WG, Jersey Citizenship: Company organized under the laws of Jersey (iv) Sir Jeremy Isaacs 44 Esplanade, St. Helier, JE4 9WG, Jersey Citizenship: British Citizen (v) Mr. Roger Nagioff 44 Esplanade, St. Helier, JE4 9WG, Jersey Citizenship: British Citizen
(d)	Title of class of securities: Common Stock, par value $0.001551 per share
(e)	CUSIP No.: G5S37H101
Item 3.	If this statement is filed pursuant to §§ 240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:
(a)	Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o);
(b)	Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c);
(c)	Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c);
(d)	Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8);
(e)	An investment adviser in accordance with § 240.13d-1(b)(1)(ii)(E);
(f)	An employee benefit plan or endowment fund in accordance with § 240.13d-1(b)(1)(ii)(F);
(g)	A parent holding company or control person in accordance with § 240.13d-1(b)(1)(ii)(G);
(h)	A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);
(i)	A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);
(j)	A non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J). If filing as a non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J), please specify the type of institution:
(k)	Group, in accordance with Rule 240.13d-1(b)(1)(ii)(K).
Item 4.	Ownership
(a)	Amount beneficially owned: As of the date hereof, Amphitryon Ltd. directly held 0 Shares. JRJ Investor 1 LP is the indirect sole shareholder of Amphitryon Ltd. JRJ Investor 1 LP is indirectly controlled by JRJ Group Limited, which is controlled by Sir Jeremy Isaacs and Mr. Roger Nagioff. As such, they may have be deemed to have or share beneficial ownership of the Shares previously held directly by Amphitryon Limited.
(b)	Percent of class:
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: 0
	(ii) Shared power to vote or to direct the vote: 0
	(iii) Sole power to dispose or to direct the disposition of: 0
	(iv) Shared power to dispose or to direct the disposition of: 0
Item 5.	Ownership of 5 Percent or Less of a Class.
	Ownership of 5 percent or less of a class
Item 6.	Ownership of more than 5 Percent on Behalf of Another Person.
	Not Applicable
Item 7.	Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.
	Not Applicable
Item 8.	Identification and Classification of Members of the Group.
	Not Applicable
Item 9.	Notice of Dissolution of Group.
	Not Applicable

Item 10.	Certifications:
	Not Applicable

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

JRJ Investor 1 LP

Signature:	/s/ Nigel Crocker
Name/Title:	Nigel Crocker / Director
Date:	08/10/2026

Amphitryon Limited (in liquidation)

Signature:	/s/ Jacques van Oorschot
Name/Title:	Jacques van Oorschot / Director
Date:	08/10/2026

JRJ Group Limited

Signature:	/s/ Nigel Crocker
Name/Title:	Nigel Crocker / Director
Date:	08/10/2026

Sir Jeremy Isaacs

Signature:	/s/ Jeremy Isaacs
Name/Title:	Jeremy Isaacs
Date:	08/10/2026

Mr. Roger Nagioff

Signature:	/s/ Roger Nagioff
Name/Title:	Roger Nagioff
Date:	08/10/2026