Plutonian Acquisition Corp II (PLUN): Magnetar group discloses 5.71% ownership stake

Rhea-AI Filing Summary

Magnetar Financial LLC and related entities reported a passive stake in Plutonian Acquisition Corp II. As of June 30, 2026, Magnetar Financial, Magnetar Capital Partners LP, Supernova Management LLC, and David J. Snyderman were each deemed to beneficially own 650,000 Class A ordinary shares of Plutonian Acquisition Corp II. These shares are held across several Magnetar-managed funds, including Constellation Master Fund, Lake Credit Fund, Structured Credit Fund, Xing He Master Fund, Alpha Star Fund, Capital Master Fund, and Waterfront Series A Fund. The position represents approximately 5.71% of the 11,383,837 Class A shares outstanding, based on issuer information. The Reporting Persons have shared voting and dispositive power over all 650,000 shares and no sole voting or dispositive power, reflecting coordinated investment management rather than individual ownership.

Key Figures

Shares beneficially owned: 650,000 shares Percent of class: 5.71% Shares outstanding: 11,383,837 shares +5 more

8 metrics

Shares beneficially owned 650,000 shares Class A ordinary shares of Plutonian Acquisition Corp II held as of June 30, 2026

Percent of class 5.71% Portion of Plutonian Acquisition Corp II Class A shares beneficially owned by Reporting Persons

Shares outstanding 11,383,837 shares Class A shares outstanding used to compute ownership percentage, from Form 10-Q filed July 15, 2026

Constellation Master Fund holdings 156,000 shares PLUN Class A shares held for Magnetar Constellation Master Fund, Ltd

Lake Credit Fund holdings 110,500 shares PLUN Class A shares held for Magnetar Lake Credit Fund LLC

Structured Credit Fund holdings 136,500 shares PLUN Class A shares held for Magnetar Structured Credit Fund, LP

Shared voting power 650,000 shares Shares over which Reporting Persons have shared power to vote or direct the vote

Sole voting power 0 shares Shares over which Reporting Persons have sole power to vote or direct the vote

Key Terms

beneficial owner, shared voting power, shared dispositive power, investment adviser, +2 more

6 terms

beneficial owner financial

"The Shares held by the Magnetar Funds represent approximately 5.71% of the total number of Shares outstanding"

A beneficial owner is the person who ultimately owns or controls a financial asset or property, even if their name isn't directly on official documents. Think of it like someone who secretly holds the keys to a safe deposit box—others may appear to have access, but the true owner is the one who benefits from what's inside. Identifying beneficial owners helps ensure transparency and prevent illegal activities like money laundering or fraud.

shared voting power financial

"Shared power to vote or to direct the vote: 650,000"

Shared voting power occurs when two or more parties jointly have the right to vote or decide how a block of company shares is cast, like co-owners who must agree before moving a piece of furniture. Investors care because who controls voting rights affects board elections, major corporate decisions and takeover outcomes, and shared control can alter regulatory disclosures and the practical influence any holder has over a company’s direction and value.

shared dispositive power financial

"Shared power to dispose or to direct the disposition of: 650,000"

investment adviser financial

"Magnetar Financial serves as the investment adviser to the Magnetar Funds"

An investment adviser is a person or firm that professionally manages money and gives recommendations about buying, selling, or holding investments. Like a financial coach or guide, they have a legal duty to act in a client's best financial interest, so their advice, fees and potential conflicts can directly affect returns and risk — making their role important for investors who want informed, accountable help with portfolios.

Schedule 13G regulatory

"The Shares held by the Magnetar Funds represent approximately 5.71% of the total number of Shares outstanding"

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.

power of attorney regulatory

"Power of Attorney, dated as of December 22, 2022 filed by the Reporting Persons"

A power of attorney is a legal document that allows one person to make decisions and act on behalf of another person, often in financial or legal matters. It’s like giving someone a trusted helper or agent the authority to handle important tasks if you are unable to do so yourself. This matters to investors because it can impact how their assets are managed or transferred if they become unable to oversee their affairs.

FAQ

What ownership stake in PLUN does Magnetar report on this Schedule 13G?

Magnetar and related entities report beneficial ownership of 650,000 Class A ordinary shares of Plutonian Acquisition Corp II (PLUN), representing approximately 5.71% of the company’s outstanding Class A shares as of June 30, 2026.

How many Plutonian Acquisition Corp II shares are outstanding according to this filing for PLUN?

The filing states there were approximately 11,383,837 Class A shares outstanding of Plutonian Acquisition Corp II, based on information from a Form 10-Q filed on July 15, 2026, used to calculate Magnetar’s 5.71% ownership.

Which Magnetar funds hold PLUN shares and in what amounts?

The 650,000 PLUN shares are spread across multiple Magnetar funds, including 156,000 for Constellation Master Fund, 110,500 for Lake Credit Fund, 136,500 for Structured Credit Fund, 104,000 for Xing He Master Fund, 117,000 for Alpha Star Fund, 6,500 for Capital Master Fund, and 19,500 for Waterfront Series A Fund.

Does Magnetar have sole or shared voting power over its PLUN holdings?

The Reporting Persons have 0 shares with sole voting power and 650,000 shares with shared voting power in PLUN. They also report 0 shares with sole dispositive power and 650,000 shares with shared dispositive power over the same holdings.

Who are the Reporting Persons on this PLUN Schedule 13G?

The Reporting Persons are Magnetar Financial LLC, Magnetar Capital Partners LP, Supernova Management LLC, and David J. Snyderman. Magnetar Financial acts as investment adviser to the Magnetar funds that hold the PLUN shares, with the other entities serving as parent and general partner entities.

What is David J. Snyderman’s role in the PLUN ownership structure?

David J. Snyderman is identified as the administrative manager of Supernova Management LLC, which is the general partner of Magnetar Capital Partners LP. He is listed as a Reporting Person and is deemed to share beneficial ownership of 650,000 PLUN shares with the affiliated entities.

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Available on EDGAR 08/13/2026 - 06:20 AM Accepted by SEC EDGAR 08/13/2026 - 06:20 AM Learn about SEC filing dates

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

PLUTONIAN ACQUISITION CORP II

(Name of Issuer)

Class A ordinary shares, par value $0.0001

(Title of Class of Securities)

G71382108

(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): G71382108

1

Names of Reporting Persons

MAGNETAR FINANCIAL LLC

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

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 650,000.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 650,000.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

650,000.00

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)

5.71 %

12

Type of Reporting Person (See Instructions)

IA, OO

SCHEDULE 13G

CUSIP Number(s): G71382108

1

Names of Reporting Persons

MAGNETAR CAPITAL PARTNERS 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

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 650,000.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 650,000.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

650,000.00

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)

5.71 %

12

Type of Reporting Person (See Instructions)

HC, PN

SCHEDULE 13G

CUSIP Number(s): G71382108

1

Names of Reporting Persons

SUPERNOVA MANAGEMENT LLC

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

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 650,000.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 650,000.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

650,000.00

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)

5.71 %

12

Type of Reporting Person (See Instructions)

HC, OO

SCHEDULE 13G

CUSIP Number(s): G71382108

1

Names of Reporting Persons

DAVID J. SNYDERMAN

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 STATES

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 650,000.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 650,000.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

650,000.00

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)

5.71 %

12

Type of Reporting Person (See Instructions)

HC, IN

SCHEDULE 13G

Item 1.
(a)	Name of issuer: PLUTONIAN ACQUISITION CORP II
(b)	Address of issuer's principal executive offices: 1216 Broadway, NEW YORK, NY 10001
Item 2.
(a)	Name of person filing: This statement is filed on behalf of each of the following person (collectively, the "Reporting Persons"): i) Magnetar Financial LLC ("Magnetar Financial"); ii) Magnetar Capital Partners LP ("Magnetar Capital Partners"); iii) Supernova Management LLC ("Supernova Management"); and iv) David J. Snyderman ("Mr. Snyderman"). This statement relates to the Shares (as defined herein) held for Magnetar Constellation Master Fund, Ltd ("Constellation Master Fund"), Magnetar Xing He Master Fund Ltd ("Xing He Master Fund"), and Magnetar Capital Master Fund Ltd ("Capital Master Fund"), all Cayman Islands exempted companies; Magnetar Structured Credit Fund, LP ("Structured Credit Fund"), a Delaware limited partnership; Magnetar Alpha Star Fund LLC ("Alpha Star Fund"), Magnetar Lake Credit Fund LLC ("Lake Credit Fund"), and Magnetar Waterfront Series A LLC ("Waterfront Series A Fund"), all Delaware limited liability companies; collectively (the "Magnetar Funds"). Magnetar Financial serves as the investment adviser to the Magnetar Funds, and as such, Magnetar Financial exercises voting and investment power over the Shares held for the Magnetar Funds' accounts. Magnetar Capital Partners serves as the sole member and parent holding company of Magnetar Financial. Supernova Management is the general partner of Magnetar Capital Partners. The administrative manager of Supernova Management is Mr. Snyderman.
(b)	Address or principal business office or, if none, residence: The address of the principal business office of each of Magnetar Financial, Magnetar Capital Partners, Supernova Management, and Mr. Snyderman is 1603 Orrington Avenue, 13th Floor, Evanston, Illinois 60201.
(c)	Citizenship: Place of Organization. i) Magnetar Financial is a Delaware limited liability company; ii) Magnetar Capital Partners is a Delaware limited partnership; iii) Supernova Management is a Delaware limited liability company; and iv) Mr. Snyderman is a citizen of the United States of America.
(d)	Title of class of securities: Class A ordinary shares, par value $0.0001
(e)	CUSIP Number(s): G71382108
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 June 30, 2026, each of Magnetar Financial, Magnetar Capital Partners, Supernova Management and Mr. Snyderman held 650,000 Shares. The amount consists of (A) 156,000 Shares held for the account of Constellation Master Fund; (B) 110,500 Shares held for the account of Lake Credit Fund; (C) 136,500 Shares held for the account of Structured Credit Fund; (D) 104,000 Shares held for the account of Xing He Master Fund; (E) 117,000 Shares held for the account of Alpha Star Fund; (F) 6,500 Shares held for the account of Capital Master Fund; and (G) 19,500 shares held for the account of Waterfront Series A Fund. The Shares held by the Magnetar Funds represent approximately 5.71% of the total number of Shares outstanding (calculated pursuant to Rule 13d-3(d)(1)(i) of the outstanding shares of the Issuer).
(b)	Percent of class: As of June 30, 2026, each of the Reporting Persons were deemed to be the beneficial owner constituting approximately 5.71% of the total number of shares outstanding (based upon the information provided by the Issuer in Form 10-Q filed on July 15, 2026, there were approximately 11,383,837 Shares outstanding).
(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: 650,000
	(iii) Sole power to dispose or to direct the disposition of: 0
	(iv) Shared power to dispose or to direct the disposition of: 650,000
Item 5.	Ownership of 5 Percent or Less of a Class.
	Not Applicable
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:

By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under § 240.14a-11.

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.

MAGNETAR FINANCIAL LLC

Signature:	/s/ Hayley Stein
Name/Title:	Name:Hayley Stein, Title: Attorney-in-fact for David J. Snyderman, Administrative Manager of Supernova Management LLC
Date:	08/13/2026

MAGNETAR CAPITAL PARTNERS LP

Signature:	/s/ Hayley Stein
Name/Title:	Name:Hayley Stein, Title: Attorney-in-fact for David J. Snyderman, Administrative Manager of Supernova Management LLC
Date:	08/13/2026

SUPERNOVA MANAGEMENT LLC

Signature:	/s/ Hayley Stein
Name/Title:	Name:Hayley Stein, Title: Attorney-in-fact for David J. Snyderman, Administrative Manager of Supernova Management LLC
Date:	08/13/2026

DAVID J. SNYDERMAN

Signature:	/s/ Hayley Stein
Name/Title:	Name:Hayley Stein, Title: Attorney-in-fact for David J. Snyderman, Administrative Manager of Supernova Management LLC
Date:	08/13/2026

Comments accompanying signature: MAGNETAR FINANCIAL LLC BY: Magnetar Capital Partners LP, its Sole Member BY: Supernova Management LLC, its General Partner MAGNETAR CAPITAL PARTNERS LP By: Supernova Management LLC, its General Partner

Exhibit Information

99.1 Joint Filing Agreement, dated as of August 13, 2026, among the Reporting Persons. 99.2 Power of Attorney, dated as of December 22, 2022 filed by the Reporting Persons on August 13, 2026.