Magnetar Financial LLC, Magnetar Capital Partners LP, Supernova Management LLC and managing member David J. Snyderman filed Amendment No. 1 to Schedule 13G for HCM II Acquisition Corp. (CUSIP G43658106).
The group reports beneficial ownership of 1,397,166 Class A ordinary shares, representing 6.07 % of the 23 million shares outstanding as of 30 Jun 2025. Holdings are spread across eight Magnetar-managed funds, the largest being Constellation Master Fund (324,605 sh) and Lake Credit Fund (239,923 sh).
The Reporting Persons have shared voting and dispositive power over all disclosed shares and no sole power. Certification states the shares were acquired in the ordinary course of business with no intent to influence control. The filing is made under Rule 13d-1(b) as a passive institutional investment. Signatures are dated 8 Aug 2025.
Magnetar’s disclosure crosses the 5 % threshold, triggering Schedule 13G filing. Because voting/dispositive power is shared and certified as passive, the stake does not suggest activist intentions. While the position size is modest, Magnetar’s reputation as an event-driven investor signals that institutional money is monitoring the SPAC’s future business-combination prospects. The filing neither alters capital structure nor guidance, so near-term valuation impact should be muted.
TL;DR: Magnetar’s 1.4 m-share position adds credible arbitrage capital—marginally positive for deal execution.
Event-driven funds like Magnetar often accumulate SPAC shares to arbitrage redemption vs. trust value or participate in post-merger upside. A 6 % block can help facilitate quorum and deal approval, potentially smoothing the de-SPAC path. However, Magnetar may also redeem if economics deteriorate, posing an overhang. Overall, presence of a sophisticated holder is slightly supportive but not transformational.
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
SCHEDULE 13G
UNDER THE SECURITIES EXCHANGE ACT OF 1934
(Amendment No. 1)
HCM II Acquisition Corp.
(Name of Issuer)
Class A ordinary shares, par value $0.0001
(Title of Class of Securities)
G43658106
(CUSIP Number)
06/30/2025
(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)
SCHEDULE 13G
CUSIP No.
G43658106
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
1,397,166.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
1,397,166.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
1,397,166.00
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)
6.07 %
12
Type of Reporting Person (See Instructions)
IA, OO
SCHEDULE 13G
CUSIP No.
G43658106
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
1,397,166.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
1,397,166.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
1,397,166.00
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)
6.07 %
12
Type of Reporting Person (See Instructions)
HC, PN
SCHEDULE 13G
CUSIP No.
G43658106
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
1,397,166.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
1,397,166.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
1,397,166.00
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)
6.07 %
12
Type of Reporting Person (See Instructions)
HC, OO
SCHEDULE 13G
CUSIP No.
G43658106
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
1,397,166.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
1,397,166.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
1,397,166.00
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)
6.07 %
12
Type of Reporting Person (See Instructions)
HC, IN
SCHEDULE 13G
Item 1.
(a)
Name of issuer:
HCM II Acquisition Corp.
(b)
Address of issuer's principal executive offices:
100 First Stamford Place Stamford, CT, 06902
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"), Magnetar SC Fund Ltd ("SC Fund"), Purpose Alternative Credit Fund Ltd ("Purpose Credit 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"), Purpose Alternative Credit Fund - T LLC ("Purpose Credit Fund - T"), 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 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 No.:
G43658106
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, 2025, each of Magnetar Financial, Magnetar Capital Partners, Supernova Management and Mr. Snyderman held 1,397,166 Shares. The amount consists of (A) 324,605 Shares held for the account of Constellation Master Fund; (B) 239,923 Shares held for the account of Lake Credit Fund; (C) 225,804 Shares held for the account of Structured Credit Fund; (D) 211,688 Shares held for the account of Xing He Master Fund; (E) 141,128 Shares held for the account of Alpha Star Fund; (F) 127,001 Shares held for the account of Purpose Credit Fund; (G) 98,787 Shares held for the account SC Fund; and (H) 28,224 Shares held for the account of Purpose Credit Fund -T.
The Shares held by the Magnetar Funds represent approximately 6.07% 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, 2025, each of the Reporting Persons were deemed to be the beneficial owner constituting approximately 6.07% of the total number of shares outstanding (based upon the information provided by the Issuer in its Form 10-Q filed with the SEC on May 20, 2025, there were approximately 23,000,000 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:
1,397,166
(iii) Sole power to dispose or to direct the disposition of:
0
(iv) Shared power to dispose or to direct the disposition of:
1,397,166
Item 5.
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:
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:
Hayley Stein, Attorney-in-fact for David J. Snyderman, Manager of Supernova Management LLC
Date:
08/08/2025
MAGNETAR CAPITAL PARTNERS LP
Signature:
/s/ Hayley Stein
Name/Title:
Hayley Stein, Attorney-in-fact for David J. Snyderman, Manager of Supernova Management LLC
Date:
08/08/2025
SUPERNOVA MANAGEMENT LLC
Signature:
/s/ Hayley Stein
Name/Title:
Hayley Stein, Attorney-in-fact for David J. Snyderman, Manager of Supernova Management LLC
Date:
08/08/2025
DAVID J. SNYDERMAN
Signature:
/s/ Hayley Stein
Name/Title:
Hayley Stein, Attorney-in-fact for David J. Snyderman, Manager of Supernova Management LLC
Date:
08/08/2025
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 8, 2025, among the Reporting Persons.
99.2 Power of Attorney, dated as of December 22, 2022 filed by the Reporting Persons on August 8, 2025.
