[SCHEDULE 13G/A] X4 Pharmaceuticals, Inc Amended Passive Investment Disclosure

Rhea-AI Filing Summary

Trails Edge Capital Partners, Trails Edge Biotechnology Master Fund, and Ortav Yehudai report beneficial ownership of 5,227,222 shares of X4 Pharmaceuticals common stock as of December 31, 2025, representing 5.8% of the company.

The position includes 2,571,478 shares held directly and 2,655,744 shares underlying prefunded warrants, all held through Trails Edge Biotechnology. The ownership percentage is based on 87,436,688 shares outstanding as of October 31, 2025. The filers certify the holdings are not for the purpose of changing or influencing control of X4 Pharmaceuticals.

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. 1)

X4 Pharmaceuticals, Inc.

(Name of Issuer)

Common Stock, par value $0.001 per share

(Title of Class of Securities)

98420X202

(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. 98420X202

1

Names of Reporting Persons

Trails Edge 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 5,227,222.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 5,227,222.00
8	Shared Dispositive Power 0.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

5,227,222.00

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)

5.8 %

12

Type of Reporting Person (See Instructions)

IA, PN

Comment for Type of Reporting Person: See Item 4 for additional information.

SCHEDULE 13G

CUSIP No. 98420X202

1

Names of Reporting Persons

Trails Edge Biotechnology Master Fund, 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

CAYMAN ISLANDS

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 5,227,222.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 5,227,222.00
8	Shared Dispositive Power 0.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

5,227,222.00

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)

5.8 %

12

Type of Reporting Person (See Instructions)

PN

Comment for Type of Reporting Person: See Item 4 for additional information.

SCHEDULE 13G

CUSIP No. 98420X202

1

Names of Reporting Persons

Ortav Yehudai

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 5,227,222.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 5,227,222.00
8	Shared Dispositive Power 0.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

5,227,222.00

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)

5.8 %

12

Type of Reporting Person (See Instructions)

IN

Comment for Type of Reporting Person: See Item 4 for additional information.

SCHEDULE 13G

Item 1.
(a)	Name of issuer: X4 Pharmaceuticals, Inc.
(b)	Address of issuer's principal executive offices: 61 North Beacon Street, 4th Floor, Boston, Massachusetts 02134
Item 2.
(a)	Name of person filing: This report on Schedule 13G is being filed by Trails Edge Capital Partners, LP, a Delaware limited partnership ("Trails Edge Capital"). Trails Edge Capital is the investment manager to Trails Edge Biotechnology Master Fund, LP, a Cayman Islands limited partnership ("Trails Edge Biotechnology") and Ortav Yehudai ("Mr. Yehudai"), the Chief Investment Officer of Trails Edge Capital. Each of Trails Edge Capital, Trails Edge Biotechnology and Mr. Yehudai are referred to individually as a "Filer" and collectively as the "Filers".
(b)	Address or principal business office or, if none, residence: The address for each Filer is 3455 Peachtree Road NE, 5th Floor, Atlanta, GA 30326.
(c)	Citizenship: See Item 4 of the cover page of each Filer.
(d)	Title of class of securities: Common Stock, par value $0.001 per share
(e)	CUSIP No.: 98420X202
Item 4.	Ownership
(a)	Amount beneficially owned: As of December 31, 2025 (the "Event Date"), each Filer may be deemed to beneficially own an aggregate of 5,227,222 shares of common stock (the "Common Stock"), par value $0.001 (the "Shares"), of X4 Pharmaceuticals, Inc. (the "Issuer"). The 5,227,222 Shares reported as beneficially owned on this Schedule 13G by each Filer consists of the following: (i) 2,571,478 Shares held directly by Trails Edge Biotechnology, and (ii) 2,655,744 Shares underlying prefunded warrants (the "Warrants") held directly by Trails Edge Biotechnology. As a result, Trails Edge Biotechnology beneficially owns 5.8% of the outstanding Shares of the Issuer as of the Event Date. Trails Edge Capital, as the investment manager to Trails Edge Biotechnology, may be deemed to beneficially own these securities. Mr. Yehudai, as the Chief Investment Officer of Trails Edge Capital, exercises voting and investment discretion with respect to these securities and as such may be deemed to beneficially own 5.8% of the outstanding Shares of the Issuer as of the Event Date. Ownership percentages are based on 87,436,688 shares of Common Stock issued and outstanding as of October 31, 2025, as reported by the Issuer in its Quarterly Report on Form 10-Q for the quarterly period ended September 30, 2025, filed with the Securities and Exchange Commission on November 5, 2025.
(b)	Percent of class: 5.8%
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: 5,227,222.00
	(ii) Shared power to vote or to direct the vote: 0
	(iii) Sole power to dispose or to direct the disposition of: 5,227,222.00
	(iv) Shared power to dispose or to direct the disposition of: 0
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 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.

Trails Edge Capital Partners, LP

Signature:	By: Trails Edge Capital Partners, LLC, GP of Trails Edge Capital Partners, LP /s/ Ortav Yehudai
Name/Title:	Ortav Yehudai / Chief Investment Officer of Trails Edge Capital Partners, LLC
Date:	02/17/2026

Trails Edge Biotechnology Master Fund, LP

Signature:	By: Trails Edge GP, LLC, GP of Trails Edge Biotechnology Fund GP, LP, GP of Trails Edge Biotechnology Master Fund, LP /s/ Ortav Yehudai
Name/Title:	Ortav Yehudai / Chief Investment Officer of Trails Edge GP, LLC
Date:	02/17/2026

Ortav Yehudai

Signature:	/s/ Ortav Yehudai
Name/Title:	Ortav Yehudai / Individual
Date:	02/17/2026

Exhibit Information

1. Joint Filing Agreement, dated August 18, 2025, by and among Trails Edge Capital, Trails Edge Biotechnology and Mr. Yehudai (incorporated by reference to Exhibit 1 to the Schedule 13G-A filed with the Securities and Exchange Commission on August 18, 2025).