[SCHEDULE 13G] X4 Pharmaceuticals, Inc. SEC Filing

Rhea-AI Filing Summary

Deep Track entities and David Kroin report beneficial ownership of 2,366,995 shares of X4 Pharmaceuticals (XFOR), representing 9.99% of the class. The filing shows shared voting and dispositive power over those shares and states the position was not acquired to change control. The beneficial-ownership calculation references the issuer's reported share counts and convertible instruments and notes the inclusion of 4,162,137 pre-funded warrants exercisable subject to a 9.99% maximum-percentage exercise limitation that prevents exercise if it would push ownership above 9.99%. The filing is a joint Schedule 13G by Deep Track Capital, LP; Deep Track Biotechnology Master Fund, Ltd.; and David Kroin and includes signatures dated August 19, 2025.

Insights

Financial Analyst

TL;DR: Reporting persons hold a disclosed 9.99% stake with shared voting power; filing signals a significant passive position below 10%.

The Schedule 13G shows an aggregate beneficial position of 2,366,995 shares representing 9.99% of X4 Pharmaceuticals' common stock, with shared voting and dispositive power. The filing explicitly states the holdings were not acquired to change or influence control. The inclusion of pre-funded warrants and an exercise cap at 9.99% is important because it limits potential immediate dilution or automatic crossing of the 10% threshold. For investors, this documents a material passive stake but does not indicate active control or a control contest.

Corporate Governance Expert

TL;DR: Joint filing documents coordinated ownership and a contractual cap preventing exercise above 9.99%, reducing immediate control implications.

The joint Schedule 13G identifies the reporting group and confirms shared voting/dispositive authority over the disclosed shares. The certification language indicates the position is not intended to change control. The stated exercise limitation on pre-funded warrants that prevents beneficial ownership exceeding 9.99% is a governance-relevant mechanism that maintains the holders below certain regulatory thresholds. This filing therefore documents transparency about a sizable stake while signaling no asserted intent to pursue control.

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

X4 Pharmaceuticals, Inc.

(Name of Issuer)

Common Stock, par value $0.001 per share

(Title of Class of Securities)

98420X202

(CUSIP Number)

08/12/2025

(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

Deep Track Capital, 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 2,366,995.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 2,366,995.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

2,366,995.00

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)

9.99 %

12

Type of Reporting Person (See Instructions)

IA, OO

SCHEDULE 13G

CUSIP No. 98420X202

1

Names of Reporting Persons

Deep Track Biotechnology Master Fund, Ltd.

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 0.00
6	Shared Voting Power 2,366,995.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 2,366,995.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

2,366,995.00

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)

9.99 %

12

Type of Reporting Person (See Instructions)

CO

SCHEDULE 13G

CUSIP No. 98420X202

1

Names of Reporting Persons

David Kroin

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 2,366,995.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 2,366,995.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

2,366,995.00

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)

9.99 %

12

Type of Reporting Person (See Instructions)

HC, IN

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: (i) Deep Track Capital, LP (ii) Deep Track Biotechnology Master Fund, Ltd. (iii) David Kroin
(b)	Address or principal business office or, if none, residence: (i) 200 Greenwich Ave, 3rd Floor, Greenwich, CT 06830 (ii) c/o Walkers Corporate Limited, 190 Elgin Ave, George Town, KY1-9001, Cayman Islands (iii) c/o Deep Track Capital, LP, 200 Greenwich Ave, 3rd Floor, Greenwich, CT 06830
(c)	Citizenship: (i) Delaware (ii) Cayman Islands (iii) United States
(d)	Title of class of securities: Common Stock, par value $0.001 per share
(e)	CUSIP No.: 98420X202
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: 2,366,995
(b)	Percent of class: 9.99%
(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: 2,366,995
	(iii) Sole power to dispose or to direct the disposition of: 0
	(iv) Shared power to dispose or to direct the disposition of: 2,366,995
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.
	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. Deep Track Capital, LP is the relevant entity for which David Kroin may be considered a control person.
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.

Deep Track Capital, LP

Signature:	/s/ David Kroin
Name/Title:	David Kroin, Managing Member of the General Partner of the Investment Adviser
Date:	08/19/2025

Deep Track Biotechnology Master Fund, Ltd.

Signature:	/s/ David Kroin
Name/Title:	David Kroin, Director
Date:	08/19/2025

David Kroin

Signature:	/s/ David Kroin
Name/Title:	David Kroin
Date:	08/19/2025

Exhibit Information

Item 4: Information with respect to the Reporting Persons' ownership of the Common Stock as of August 19, 2025, is incorporated by reference to items (5) - (9) and (11) of the cover page of the respective Reporting Person. The amount beneficially owned by each Reporting Person is determined using 23,693,644 shares, calculated using 11,408,357 Common Stock outstanding as of August 4, 2025, according to the issuer's 10-Q filed with the SEC on August 8, 2025 and the issuer's 8-K filed with the SEC on August 12, 2025, and 1,244,511 Common Stock that would be converted to Common Stock by the Reporting Person up to the Maximum Percentage. The beneficially owned shares include 4,162,137 Pre-Funded Warrants exercisable to common shares, subject to a 9.99% Maximum Percentage exercise limitation. The Issuer shall not effect the exercise of any portion of the Pre-Funded Warrants, to the extent that after giving effect to such exercise, the holder collectively would beneficially own in excess of 9.99% (the "Maximum Percentage") of the number of Common Stock outstanding immediately after giving effect to such exercise. JOINT FILING STATEMENT PURSUANT TO RULE 13d-1(k) The undersigned acknowledge and agree that the foregoing statement on SCHEDULE 13G, is filed on behalf of each of the undersigned and that all subsequent amendments to this statement on SCHEDULE 13G, shall be filed on behalf of each of the undersigned without the necessity of filing additional joint acquisition statements. The undersigned acknowledge that each shall be responsible for the timely filing of such amendments, and for the completeness and accuracy of the information concerning him or it contained therein, but shall not be responsible for the completeness and accuracy of the information concerning the others, except to the extent that he or it knows or has reason to believe that such information is inaccurate. Dated: August 19, 2025 Deep Track Capital, LP By: /s/ David Kroin David Kroin, Managing Member of the General Partner of the Investment Adviser Deep Track Biotechnology Master Fund, Ltd. By: /s/ David Kroin David Kroin, Director David Kroin By: /s/ David Kroin David Kroin

FAQ

How many XFOR shares do Deep Track and David Kroin report owning?

The filing reports 2,366,995 shares beneficially owned, representing 9.99% of X4 Pharmaceuticals common stock.

Does the filing indicate the holders intend to change control of X4 Pharmaceuticals (XFOR)?

No. The certification states the securities were not acquired to change or influence control and are not held in connection with any such transaction.

Are any warrants or convertible instruments included in the ownership calculation?

Yes. The filing states the calculation includes 4,162,137 pre-funded warrants exercisable to common shares, subject to a 9.99% exercise limitation.

What entities filed the Schedule 13G for XFOR?

The Schedule 13G was filed jointly by Deep Track Capital, LP, Deep Track Biotechnology Master Fund, Ltd., and David Kroin.

When were the signatures on this Schedule 13G dated?

All signatures on the filing are dated August 19, 2025.