[SCHEDULE 13G] SilverBox Corp V Passive Investment Disclosure (>5%)
Adage Reports 6.44% Stake in SilverBox Corp V
SilverBox Corp V received a beneficial ownership report showing that funds managed by Adage Capital Management, L.P. hold 1,750,000 Class A ordinary shares.
Rhea-AI Sentiment reads the wording of the document, how positive or negative its language is on a 1 to 5 scale. The balance of points shown with the takes weighs what the document actually discloses, so the two can disagree, for example when a trial that missed its main goal is described in upbeat language.
SilverBox Corp V received a beneficial ownership report showing that funds managed by Adage Capital Management, L.P. hold 1,750,000 Class A ordinary shares. This stake represents 6.44% of the company’s 27,195,000 Class A shares outstanding as reported in recent SilverBox SEC filings.
The shares are directly held by Adage Capital Partners, L.P., with investment authority attributed to Adage Capital Management and its principals, Robert Atchinson and Phillip Gross. The filing states the position was acquired and is held in the ordinary course of business and not for the purpose of changing or influencing control of SilverBox Corp V.
Insights
Institutional investor reports a 6.44% passive stake in SilverBox.
Adage Capital Management, L.P. and related reporting persons disclose beneficial ownership of 1,750,000 Class A ordinary shares of SilverBox Corp V, representing 6.44% of the outstanding Class A shares as referenced in recent company SEC documents.
The shares are held through Adage Capital Partners, L.P., with Adage acting as investment manager and Robert Atchinson and Phillip Gross identified through their roles in related general partner and advisory entities. The filing characterizes the position as held in the ordinary course of business.
The certification explicitly states the holdings were not acquired and are not held to change or influence control of SilverBox. As a result, this appears to be a standard institutional ownership disclosure under beneficial ownership rules, and its impact on the broader investment thesis is limited.
FAQ
AI-generated questions and answers. How Rhea-AI works. Not financial advice.
How many SilverBox Corp V (SBXE) shares does Adage Capital beneficially own?
Adage Capital, through Adage Capital Partners, beneficially owns 1,750,000 Class A ordinary shares of SilverBox Corp V. This amount is disclosed as being held for investment purposes, with voting and dispositive powers shared among the reporting persons listed in the Schedule 13G filing.
What percentage of SilverBox Corp V (SBXE) does Adage Capital’s stake represent?
Adage Capital’s reported holding represents 6.44% of SilverBox Corp V’s Class A ordinary shares. This percentage is calculated against 27,195,000 Class A shares outstanding, as described in SilverBox’s prospectus and related Form 8-K after completion of its offering and related transactions.
Who are the reporting persons in the SilverBox Corp V (SBXE) Schedule 13G filing?
The reporting persons are Adage Capital Management, L.P., and individuals Robert Atchinson and Phillip Gross. Adage acts as investment manager for Adage Capital Partners, while Atchinson and Gross are managing members of related general partner and advisory entities connected to the SilverBox share holdings.
Is Adage Capital’s SilverBox Corp V (SBXE) position intended to influence control?
The filing states the securities were acquired and are held in the ordinary course of business and not for the purpose, or with the effect, of changing or influencing control of SilverBox Corp V, other than activities solely in connection with a nomination under the cited proxy rule.
What class of SilverBox Corp V (SBXE) securities is reported in this Schedule 13G?
The Schedule 13G covers Class A ordinary shares of SilverBox Corp V, each with a par value of $0.0001 per share. The CUSIP for this class is G8148S107, and the filing discloses ownership and voting/dispositive power over these specific securities.
As of what date is Adage Capital’s SilverBox Corp V (SBXE) ownership reported?
The beneficial ownership information is reported as of December 31, 2025. This date is identified as the event requiring the filing, aligning the 1,750,000 Class A shares and 6.44% ownership figure with SilverBox’s then-outstanding share count disclosed in its December 2025 SEC filings.
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
SCHEDULE 13G
UNDER THE SECURITIES EXCHANGE ACT OF 1934
SilverBox Corp V
(Name of Issuer)
Class A Ordinary Shares, par value $0.0001 per share
(Title of Class of Securities)
G8148S107
(CUSIP Number)
12/31/2025
(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.
G8148S107
1
Names of Reporting Persons
Adage Capital Management, L.P.
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
1,750,000.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
1,750,000.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
1,750,000.00
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)
6.44 %
12
Type of Reporting Person (See Instructions)
IA, PN
SCHEDULE 13G
CUSIP No.
G8148S107
1
Names of Reporting Persons
Robert Atchinson
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
1,750,000.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
1,750,000.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
1,750,000.00
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)
6.44 %
12
Type of Reporting Person (See Instructions)
HC, IN
SCHEDULE 13G
CUSIP No.
G8148S107
1
Names of Reporting Persons
Phillip Gross
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
1,750,000.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
1,750,000.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
1,750,000.00
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)
6.44 %
12
Type of Reporting Person (See Instructions)
HC, IN
SCHEDULE 13G
Item 1.
(a)
Name of issuer:
SilverBox Corp V
(b)
Address of issuer's principal executive offices:
8701 Bee Cave Road, East Building, Suite 310, Austin, TX, 78746
Item 2.
(a)
Name of person filing:
This statement is filed by:
(i) Adage Capital Management, L.P., a Delaware limited partnership ("ACM"), as the investment manager of Adage Capital Partners, L.P., a Delaware limited partnership ("ACP"), with respect to the Class A ordinary shares, par value $0.0001 per share ("Class A Ordinary Shares") of SilverBox Corp V, a Cayman Islands exempted company (the "Company") directly held by ACP;
(ii) Robert Atchinson ("Mr. Atchinson"), as (1) managing member of Adage Capital Advisors, L.L.C., a limited liability company organized under the laws of the State of Delaware ("ACA"), managing member of Adage Capital Partners GP, L.L.C., a limited liability company organized under the laws of the State of Delaware ("ACPGP"), general partner of ACP and (2) managing member of Adage Capital Partners LLC, a Delaware limited liability company ("ACPLLC"), general partner of ACM, with respect to the Class A Ordinary Shares directly held by ACP; and
(iii) Phillip Gross ("Mr. Gross"), as (1) managing member of ACA, managing member of ACPGP and (2) managing member of ACPLLC, general partner of ACM, with respect to the Class A Ordinary Shares directly held by ACP.
The foregoing persons are hereinafter sometimes collectively referred to as the "Reporting Persons." Any disclosures herein with respect to persons other than the Reporting Persons are made on information and belief after making inquiry to the appropriate party.
The filing of this statement should not be construed in and of itself as an admission by any Reporting Person as to beneficial ownership of the securities reported herein.
(b)
Address or principal business office or, if none, residence:
The address of the business office of each of the Reporting Persons is 200 Clarendon Street, 52nd Floor, Boston, Massachusetts 02116.
(c)
Citizenship:
ACM is a limited partnership organized under the laws of the State of Delaware. Messrs. Gross and Atchinson are citizens of the United States.
(d)
Title of class of securities:
Class A Ordinary Shares, par value $0.0001 per share
(e)
CUSIP No.:
G8148S107
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:
The information required by Item 4(a) is set forth in Row 9 of the cover page for each of the Reporting Persons and is incorporated herein by reference.
The percentage set forth in this Schedule 13G is calculated based upon an aggregate of 27,195,000 Class A Ordinary Shares outstanding, as reported in the Company's Prospectus filed pursuant to Rule 424(b)(4) with the Securities and Exchange Commission on December 3, 2025 and in the Company's Current Report on Form 8-K filed with the Securities and Exchange Commission on December 4, 2025, after giving effect to the completion of the offering, the consummation of the simultaneous private placement and the full exercise of the underwriters' over-allotment option, all as described therein.
(b)
Percent of class:
6.44 %
(c)
Number of shares as to which the person has:
(i) Sole power to vote or to direct the vote:
The information required by Item 4(c)(i) is set forth in Row 5 of the cover page for each of the Reporting Persons and is incorporated herein by reference.
(ii) Shared power to vote or to direct the vote:
The information required by Item 4(c)(ii) is set forth in Row 6 of the cover page for each of the Reporting Persons and is incorporated herein by reference.
(iii) Sole power to dispose or to direct the disposition of:
The information required by Item 4(c)(iii) is set forth in Row 7 of the cover page for each of the Reporting Persons and is incorporated herein by reference.
(iv) Shared power to dispose or to direct the disposition of:
The information required by Item 4(c)(iv) is set forth in Row 8 of the cover page for each of the Reporting Persons and is incorporated herein by reference.
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.
If any other person is known to have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, such securities, a statement to that effect should be included in response to this item and, if such interest relates to more than 5 percent of the class, such person should be identified. A listing of the shareholders of an investment company registered under the Investment Company Act of 1940 or the beneficiaries of employee benefit plan, pension fund or endowment fund is not required.
See Item 2(a).
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.
Adage Capital Management, L.P.
Signature:
/s/ Robert Atchinson
Name/Title:
By: Adage Capital Partners LLC, its General Partner, By: Robert Atchinson, its Managing Member
