Bank of Montreal reports no GP-Act III (GPAT) ownership in 13G/A update

Rhea-AI Filing Summary

Bank of Montreal and several affiliated entities filed an amended Schedule 13G reporting that they beneficially own 0 common shares of GP-Act III Acquisition Corp., representing 0% of the class as of December 31, 2025.

The filing confirms they have no sole or shared voting or dispositive power over any GP-Act III shares and state that any securities referenced were acquired and are held in the ordinary course of business, not to change or influence control of the company.

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. 1)

GP-Act III Acquisition Corp.

(Name of Issuer)

Common

(Title of Class of Securities)

G4035N103

(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. G4035N103

1

Names of Reporting Persons

Bank of Montreal

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

CANADA (FEDERAL LEVEL)

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)

HC

SCHEDULE 13G

CUSIP No. G4035N103

1

Names of Reporting Persons

BANK OF MONTREAL HOLDING INC.

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

CANADA (FEDERAL LEVEL)

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)

BK

SCHEDULE 13G

CUSIP No. G4035N103

1

Names of Reporting Persons

BMO NESBITT BURNS INC.

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

CANADA (FEDERAL LEVEL)

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)

BD

SCHEDULE 13G

CUSIP No. G4035N103

1

Names of Reporting Persons

BANK OF MONTREAL EUROPE PUBLIC LIMITED COMPANY

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

IRELAND

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)

BK

SCHEDULE 13G

Item 1.
(a)	Name of issuer: GP-Act III Acquisition Corp.
(b)	Address of issuer's principal executive offices: 300 PARK AVENUE, 2ND FLOOR, NEW YORK, NEW YORK 10022
Item 2.
(a)	Name of person filing: Bank of Montreal BANK OF MONTREAL HOLDING INC. BMO NESBITT BURNS INC. BANK OF MONTREAL EUROPE PUBLIC LIMITED COMPANY
(b)	Address or principal business office or, if none, residence: 1 First Canadian Place Toronto, Ontario, Canada M5X1A1
(c)	Citizenship: Bank of Montreal - CANADA (FEDERAL LEVEL) BANK OF MONTREAL HOLDING INC. - CANADA (FEDERAL LEVEL) BMO NESBITT BURNS INC. - CANADA (FEDERAL LEVEL) BANK OF MONTREAL EUROPE PUBLIC LIMITED COMPANY - IRELAND
(d)	Title of class of securities: Common
(e)	CUSIP No.: G4035N103
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: 0
(b)	Percent of class: 0 %
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: Bank of Montreal - 0 BANK OF MONTREAL HOLDING INC. - 0 BMO NESBITT BURNS INC. - 0 BANK OF MONTREAL EUROPE PUBLIC LIMITED COMPANY - 0
	(ii) Shared power to vote or to direct the vote: Bank of Montreal - 0 BANK OF MONTREAL HOLDING INC. - 0 BMO NESBITT BURNS INC. - 0 BANK OF MONTREAL EUROPE PUBLIC LIMITED COMPANY - 0
	(iii) Sole power to dispose or to direct the disposition of: Bank of Montreal - 0 BANK OF MONTREAL HOLDING INC. - 0 BMO NESBITT BURNS INC. - 0 BANK OF MONTREAL EUROPE PUBLIC LIMITED COMPANY - 0
	(iv) Shared power to dispose or to direct the disposition of: Bank of Montreal - 0 BANK OF MONTREAL HOLDING INC. - 0 BMO NESBITT BURNS INC. - 0 BANK OF MONTREAL EUROPE PUBLIC LIMITED COMPANY - 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.
	If a parent holding company has filed this schedule, pursuant to Rule 13d-1(b)(ii)(G), so indicate under Item 3(g) and attach an exhibit stating the identity and the Item 3 classification of the relevant subsidiary. If a parent holding company has filed this schedule pursuant to Rule 13d-1(c) or Rule 13d-1(d), attach an exhibit stating the identification of the relevant subsidiary. See Documents
Item 8.	Identification and Classification of Members of the Group.
	If a group has filed this schedule pursuant to §240.13d-1(b)(1)(ii)(J), so indicate under Item 3(j) and attach an exhibit stating the identity and Item 3 classification of each member of the group. If a group has filed this schedule pursuant to §240.13d-1(c) or §240.13d-1(d), attach an exhibit stating the identity of each member of the group. Each reporting person may be deemed to be a member of a group with respect to the issuer or securities of the issuer for the purposes of Section 13(d) or 13(g) of the Act. Each reporting person declares that neither the filing of this statement nor anything herein shall be construed as an admission that such person is, for the purposes of Section13(d) or 13(g) of the Act or any other purpose, (i) acting (or has agreed or is agreeing to act) with any other person as a partnership, limited partnership, syndicate, or other group for the purpose of acquiring, holding, or disposing of securities of the issuer or otherwise with respect to the issuer or any securities of the issuer or (ii) a member of any syndicate or group with respect to the issuer or any securities of the issuer.
Item 9.	Notice of Dissolution of Group.
	Notice of dissolution of a group may be furnished as an exhibit stating the date of the dissolution and that all further filings with respect to transactions in the security reported on will be filed, if required, by members of the group, in their individual capacity. See Item 5. Each reporting person may be deemed to be a member of a group with respect to the issuer or securities of the issuer for the purposes of Section 13(d) or 13(g) of the Act. Each reporting person declares that neither the filing of this statement nor anything herein shall be construed as an admission that such person is, for the purposes of Section13(d) or 13(g) of the Act or any other purpose, (i) acting (or has agreed or is agreeing to act) with any other person as a partnership, limited partnership, syndicate, or other group for the purpose of acquiring, holding, or disposing of securities of the issuer or otherwise with respect to the issuer or any securities of the issuer or (ii) a member of any syndicate or group with respect to the issuer or any securities of the issuer.

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.

Bank of Montreal

Signature:	Kathryn Cenac
Name/Title:	Managing Director - Regulatory Solutions Group
Date:	02/12/2026

BANK OF MONTREAL HOLDING INC.

Signature:	Kathryn Cenac
Name/Title:	Managing Director - Regulatory Solutions Group
Date:	02/12/2026

BMO NESBITT BURNS INC.

Signature:	Kathryn Cenac
Name/Title:	Managing Director - Regulatory Solutions Group
Date:	02/12/2026

BANK OF MONTREAL EUROPE PUBLIC LIMITED COMPANY

Signature:	Kathryn Cenac
Name/Title:	Managing Director - Regulatory Solutions Group
Date:	02/12/2026

FAQ

What did Bank of Montreal report about its GPAT (GP-Act III) holdings?

Bank of Montreal and affiliates reported they now beneficially own 0 common shares of GP-Act III Acquisition Corp.. The Schedule 13G/A shows no voting or dispositive power over any shares and an ownership percentage of 0% of the class.

What ownership percentage of GP-Act III did Bank of Montreal disclose?

The filing discloses that Bank of Montreal and its related entities beneficially own 0% of the class of GP-Act III common shares. All categories of voting and dispositive power are listed as zero, and Item 5 notes ownership of 5 percent or less of the class.

Which entities are included in Bank of Montreal’s GPAT Schedule 13G/A filing?

The Schedule 13G/A lists Bank of Montreal, Bank of Montreal Holding Inc., BMO Nesbitt Burns Inc., and Bank of Montreal Europe Public Limited Company as reporting persons, with each entity reporting zero beneficial ownership and no voting or dispositive power over GP-Act III shares.

As of what date is Bank of Montreal’s reported GP-Act III ownership effective?

The reported ownership information is tied to an event date of December 31, 2025. As of that date, Bank of Montreal and its affiliates report beneficial ownership of 0 common shares of GP-Act III Acquisition Corp., corresponding to 0% of the outstanding class.

What does the GPAT Schedule 13G/A say about Bank of Montreal’s intent?

The certification states the securities referenced were acquired and are held in the ordinary course of business, and were not acquired or held to change or influence control of GP-Act III. It also notes no participation in transactions aimed at achieving such control.

How does the Schedule 13G/A describe group or syndicate status for GPAT?

The filing notes each reporting person may be deemed part of a group for Section 13 purposes, but expressly states the filing should not be construed as an admission that they are acting as a partnership, syndicate, or other group with respect to GP-Act III securities.