Equinox group reports 6.22M Gran Tierra shares and board presence

Rhea-AI Filing Summary

Gran Tierra Energy Inc. (GTE) received an updated Schedule 13D/A from Equinox-related investors reporting a significant stake in its common stock. The reporting group, including Equinox Partners Investment Management LLC, Equinox Partners, L.P., Kuroto Fund LP, Mason Hill Partners, LP and Sean M. Fieler, now reports beneficial ownership of 6,219,896 shares, representing 17.6% of Gran Tierra’s 35,295,753 shares outstanding as referenced in a recent Form 10-Q. The filing notes that approximately $39,183,972.34, including commissions, was used to purchase these shares using client investment capital and margin accounts where applicable. The group disclaims beneficial ownership of certain client-held shares for legal purposes. The investors also note that EPIM partner and portfolio manager Brad Virbitsky, who joined Gran Tierra’s board as an independent director effective September 30, 2025, is expected to receive Gran Tierra securities as part of his director compensation.

Insights

Activist & ownership structure analyst

Equinox group discloses a 17.6% Gran Tierra stake and a board presence.

The filing shows an investor group led by Equinox Partners Investment Management LLC reporting beneficial ownership of 6,219,896 Gran Tierra shares, or about 17.6% of the company’s common stock. That percentage is based on 35,295,753 shares outstanding, as referenced from a Form 10-Q. Different Equinox-affiliated funds hold portions of this stake, with the investment adviser and Sean M. Fieler reporting shared voting and dispositive power while formally disclaiming certain beneficial ownership.

The group states that approximately $39,183,972.34 of client capital, including commissions, was used to accumulate the position, in some cases through margin accounts. This indicates a sizable, long-term capital commitment to Gran Tierra within these portfolios. The disclosure also notes that EPIM partner Brad Virbitsky joined Gran Tierra’s board as an independent director effective September 30, 2025, and is expected to receive company securities as director compensation, further linking this shareholder group to the company’s governance.

The amendment restates ownership and funding details and confirms that, over the last 60 days, transactions in the shares are limited to those listed in an attached schedule or earlier reports. Actual implications for Gran Tierra will depend on any future actions or proposals this sizeable shareholder and its board representative may bring, which are not described in this disclosure.

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13D

Under the Securities Exchange Act of 1934

(Amendment No. 2)

Gran Tierra Energy Inc.

(Name of Issuer)

Common Stock, par value $0.001 per share

(Title of Class of Securities)

38500T200

(CUSIP Number)

Eric Wagner
Kleinberg, Kaplan, Wolff & Cohen P.C., 500 Fifth Avenue
New York, NY, 10110
(212) 880-9845

(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)

11/17/2025

(Date of Event Which Requires Filing of This Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§ 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box.

The information required on the remainder of this cover page shall not be deemed to be "filed" for the purpose of Section 18 of the Securities Exchange Act of 1934 ("Act") or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

SCHEDULE 13D

CUSIP No. 38500T200

1

Name of reporting person

Equinox Partners Investment Management LLC

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

OO

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 6,219,896.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 6,219,896.00

11

Aggregate amount beneficially owned by each reporting person

6,219,896.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

17.6 %

14

Type of Reporting Person (See Instructions)

IA

Comment for Type of Reporting Person:

Note to Row 8: Includes 2,465,673 shares of Common Stock, par value $0.001 per share (the "Shares") of Gran Tierra Energy Inc. (the "Issuer") held in one or more client accounts over which Equinox Partners Investment Management LLC, as investment advisor, has shared voting and dispositive power. The filing of this statement should not be deemed as admission that Equinox Partners Investment Management LLC is, for the purposes of Section 13 of the Act, the beneficial owner of the Shares held in such client account(s).

SCHEDULE 13D

CUSIP No. 38500T200

1

Name of reporting person

Equinox Partners, L.P.

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

WC

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 2,543,910.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 2,543,910.00

11

Aggregate amount beneficially owned by each reporting person

2,543,910.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

7.2 %

14

Type of Reporting Person (See Instructions)

PN

SCHEDULE 13D

CUSIP No. 38500T200

1

Name of reporting person

Kuroto Fund LP

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

WC

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 659,996.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 659,996.00

11

Aggregate amount beneficially owned by each reporting person

659,996.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

1.9 %

14

Type of Reporting Person (See Instructions)

PN

SCHEDULE 13D

CUSIP No. 38500T200

1

Name of reporting person

Mason Hill Partners, LP

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

WC

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 550,317.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 550,317.00

11

Aggregate amount beneficially owned by each reporting person

550,317.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

1.6 %

14

Type of Reporting Person (See Instructions)

PN

SCHEDULE 13D

CUSIP No. 38500T200

1

Name of reporting person

Sean M. Fieler

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

OO

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

UNITED STATES

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 6,219,896.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 6,219,896.00

11

Aggregate amount beneficially owned by each reporting person

6,219,896.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

17.6 %

14

Type of Reporting Person (See Instructions)

IN

Comment for Type of Reporting Person:

Note to Row 8: See Footnote 1 on page 2. The filing of this statement should not be deemed an admission that Mr. Fieler is, for the purposes of Section 13 of the Act, the beneficial owner of the Shares held in such client account(s).

SCHEDULE 13D

Item 1.	Security and Issuer
(a)	Title of Class of Securities: Common Stock, par value $0.001 per share
(b)	Name of Issuer: Gran Tierra Energy Inc.
(c)	Address of Issuer's Principal Executive Offices: 500 Centre Street S.E., Calgary, ALBERTA, CANADA , T2G 1A6.
Item 1 Comment: The following constitutes Amendment No. 2 (this "Amendment No. 2") to the Schedule 13D (as previously amended, the "Schedule 13D") filed by the undersigned with respect to shares of the Common Stock, par value $0.001 per share (the "Shares") of Gran Tierra Energy Inc. (the "Issuer"). This Amendment No. 2 amends the Schedule 13D as specifically set forth herein.
Item 3.	Source and Amount of Funds or Other Consideration
	Item 3 of the Schedule 13D is hereby amended and restated in its entirety as follows: All of the Shares to which this Schedule 13D relates were purchased using the investment capital of the applicable clients of EPIM. The aggregate amount of funds used for the purchase of the Shares held by the Reporting Persons is approximately $39,183,972.34, including commissions. The Reporting Persons may effect purchases of Shares through margin accounts maintained for EPIM's clients with prime brokers, which extend margin credit as and when required to open or carry positions in their margin accounts, subject to applicable federal margin regulations, stock exchange rules and such firms' credit policies. Shares may be held in margin accounts and may be pledged as collateral security for the repayment of debit balances in such accounts. Since other securities may be held in such margin accounts, it may not be possible to determine the amounts, if any, of margin used to purchase the Shares.
Item 5.	Interest in Securities of the Issuer
(a)	Item 5 of the Schedule 13D is hereby amended and restated in its entirety as follows: (a) - (b) The aggregate percentage of Shares reported owned by the Reporting Persons is based upon 35,295,753 Shares outstanding, which is the total number of Shares outstanding as reported in the Issuer's Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission on October 31, 2025. As of the date hereof, the Reporting Persons beneficially own an aggregate of 6,219,896 Shares, constituting approximately 17.6% of the outstanding Shares. See rows (11) and (13) of the cover pages to this Schedule 13D for the aggregate number of Shares and percentage of the outstanding Shares beneficially owned by each of the Reporting Persons. See rows (7) through (10) of the cover pages to this Schedule 13D, including the notes relating thereto, for the number of Shares as to which each Reporting Person has the sole or shared power to vote or direct the vote and the sole or shared power to dispose or to direct the disposition. The filing of this Schedule 13D shall not be deemed an admission that the Reporting Persons are, for purposes of Section 13(d) of the Securities Exchange Act of 1934, as amended, the beneficial owners of any securities of the Issuer that he or it does not directly own. Each of the Reporting Persons specifically disclaims beneficial ownership of the securities reported herein that he or it does not directly own. The Reporting Persons expect that Brad Virbitsky, a portfolio manager and partner at EPIM who was appointed to the Issuer's Board of Directors as an independent director effective September 30, 2025, will be awarded certain securities of the Issuer as compensation for his serving as a member of the Issuer's Board of Directors.
(b)	See Item 5(a).
(c)	During the past sixty (60) days, the Reporting Persons have not entered into any transactions in the Shares except as set forth on Schedule 1 hereto or as previously reported on Schedule 13D.
(d)	No Person is known to the Reporting Persons to have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, any Shares that may be beneficially owned by the Reporting Persons.
(e)	Not applicable.
Item 7.	Material to be Filed as Exhibits.
	Exhibit 99 - Schedule 1

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.

Equinox Partners Investment Management LLC

Signature:	/s/ Sean M. Fieler
Name/Title:	Manager
Date:	11/19/2025

Equinox Partners, L.P.

Signature:	/s/ Sean M. Fieler
Name/Title:	Manager of Equinox Partners Investment Management LLC, the Investment Manager of Equinox Partners, L.P.
Date:	11/19/2025

Kuroto Fund LP

Signature:	/s/ Sean M. Fieler
Name/Title:	Manager of Equinox Partners Investment Management LLC, the Investment Manager of Kuroto Fund LP
Date:	11/19/2025

Mason Hill Partners, LP

Signature:	/s/ Sean M. Fieler
Name/Title:	Manager of Equinox Partners Investment Management LLC, the Investment Manager of Mason Hill Partners, LP
Date:	11/19/2025

Sean M. Fieler

Signature:	/s/ Sean M. Fieler
Name/Title:	Sean M. Fieler
Date:	11/19/2025

FAQ

What ownership stake in Gran Tierra Energy (GTE) is reported in this Schedule 13D/A amendment?

The reporting group led by Equinox Partners Investment Management LLC discloses beneficial ownership of 6,219,896 Gran Tierra Energy common shares, representing approximately 17.6% of the outstanding common stock based on 35,295,753 shares outstanding.

Who are the main reporting persons in this Gran Tierra (GTE) Schedule 13D/A filing?

The reporting persons are Equinox Partners Investment Management LLC, Equinox Partners, L.P., Kuroto Fund LP, Mason Hill Partners, LP, and Sean M. Fieler, each reporting specific share amounts and shared voting and dispositive power over Gran Tierra common stock.

How much capital was used by the Equinox group to buy its Gran Tierra Energy shares?

The filing states that an aggregate of approximately $39,183,972.34, including commissions, was used to purchase the Gran Tierra Energy shares held by the reporting persons’ clients, with some purchases made through margin accounts.

What portion of Gran Tierra (GTE) shares does each Equinox-affiliated fund report owning?

Equinox Partners, L.P. reports 2,543,910 shares (about 7.2% of the class). Kuroto Fund LP reports 659,996 shares (about 1.9%), and Mason Hill Partners, LP reports 550,317 shares (about 1.6%), all with shared voting and dispositive power.

Does the Equinox group have board representation at Gran Tierra Energy?

Yes. The filing notes that Brad Virbitsky, a portfolio manager and partner at Equinox Partners Investment Management LLC, was appointed to Gran Tierra’s Board of Directors as an independent director effective September 30, 2025 and is expected to receive Gran Tierra securities as compensation.

How was the percentage ownership of 17.6% in Gran Tierra (GTE) calculated in this filing?

The reported 17.6% ownership is based on total beneficial ownership of 6,219,896 shares divided by 35,295,753 Gran Tierra shares outstanding, which the filing cites from the company’s Form 10-Q filed on October 31, 2025.

Have the reporting persons disclosed any recent trading activity in Gran Tierra shares?

The filing states that during the past 60 days, the reporting persons have not entered into any transactions in Gran Tierra shares except as listed on an attached Schedule 1 or as previously reported.