Morgan Stanley discloses 9.4% stake in X4 Pharma

Morgan Stanley and its investment management arm have reported a significant passive stake in X4 Pharmaceuticals, Inc. They beneficially own 8,196,489 shares of X4 common stock, representing 9.4% of the outstanding class as of December 31, 2025.

Accepted by SEC EDGAR 02/12/2026 - 02:28 PM EST Learn about SEC filing dates

Rhea-AI Filing Summary

Morgan Stanley and its investment management arm have reported a significant passive stake in X4 Pharmaceuticals, Inc. They beneficially own 8,196,489 shares of X4 common stock, representing 9.4% of the outstanding class as of December 31, 2025.

The filing shows no sole voting or dispositive power; all 8,196,489 shares are held with shared voting and shared dispositive power. The firms certify the holdings are in the ordinary course of business and not for the purpose of changing or influencing control of X4 Pharmaceuticals.

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

What stake does Morgan Stanley hold in X4 Pharmaceuticals (XFOR)?

Morgan Stanley and its investment management unit beneficially own 8,196,489 shares of X4 Pharmaceuticals common stock, or 9.4% of the class. The position is reported with shared voting and shared dispositive power rather than sole control over the shares.

Is Morgan Stanley’s ownership in X4 Pharmaceuticals (XFOR) a passive investment?

Yes. Morgan Stanley certifies the X4 Pharmaceuticals shares were acquired and are held in the ordinary course of business. They state the holdings are not for changing or influencing control of X4, but as a passive investment consistent with regulatory requirements.

Who are the reporting persons in the X4 Pharmaceuticals (XFOR) Schedule 13G?

The reporting persons are Morgan Stanley and Morgan Stanley Investment Management Inc., both organized in Delaware. They file jointly under a joint filing agreement and report shared voting and dispositive power over the X4 Pharmaceuticals common stock position disclosed.

How much voting power does Morgan Stanley have over its X4 Pharmaceuticals (XFOR) shares?

Morgan Stanley reports zero sole voting power and zero sole dispositive power over X4 shares. It reports shared voting power and shared dispositive power over 8,196,489 shares, reflecting that decisions regarding these shares are made jointly rather than individually.

What percentage of X4 Pharmaceuticals’ common stock does 8,196,489 shares represent?

The 8,196,489 X4 Pharmaceuticals common shares reported by Morgan Stanley represent 9.4% of the outstanding common stock. This places Morgan Stanley and its investment management arm among significant institutional holders crossing the 5% regulatory disclosure threshold.

Does Morgan Stanley intend to influence control of X4 Pharmaceuticals (XFOR)?

According to the certification, Morgan Stanley does not hold the X4 Pharmaceuticals securities to change or influence control of the company. The shares are described as acquired and held in the ordinary course of business, consistent with a passive Schedule 13G filing.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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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

(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

Morgan Stanley

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 8,196,489.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 8,196,489.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

8,196,489.00

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)

9.4 %

12

Type of Reporting Person (See Instructions)

HC, CO

SCHEDULE 13G

CUSIP No. 98420X202

1

Names of Reporting Persons

Morgan Stanley Investment Management 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

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 8,196,455.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 8,196,455.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

8,196,455.00

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)

9.4 %

12

Type of Reporting Person (See Instructions)

IA, CO

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, MA, 02134
Item 2.
(a)	Name of person filing: 1: Morgan Stanley 2: Morgan Stanley Investment Management Inc.
(b)	Address or principal business office or, if none, residence: 1: 1585 Broadway, New York, NY 10036 ;2: 1585 Broadway New York, NY 10036
(c)	Citizenship: 1: Delaware 2: Delaware
(d)	Title of class of securities: Common Stock
(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: See the response(s) to Item 9 on the attached cover page(s).
(b)	Percent of class: 9.4 %
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: See the response(s) to Item 5 on the attached cover page(s).
	(ii) Shared power to vote or to direct the vote: See the response(s) to Item 6 on the attached cover page(s).
	(iii) Sole power to dispose or to direct the disposition of: See the response(s) to Item 7 on the attached cover page(s).
	(iv) Shared power to dispose or to direct the disposition of: See the response(s) to Item 8 on the attached cover page(s).
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.
	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 Exhibit 99.2
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. * In Accordance with the Securities and Exchange Commission Release No. 34-39538 (January 12, 1998) (the "Release"), this filing reflects the securities beneficially owned, or that may be deemed to be beneficially owned, by certain operating units (collectively, the "MS Reporting Units") of Morgan Stanley and its subsidiaries and affiliates (collectively, "MS"). This filing does not reflect securities, if any, beneficially owned by any operating units of MS whose ownership of securities is disaggregated from that of the MS Reporting Units in accordance with the Release.

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.

Morgan Stanley

Signature:	Chris O'Hara
Name/Title:	Authorized Signatory, Morgan Stanley
Date:	02/12/2026

Morgan Stanley Investment Management Inc.

Signature:	Deidre A. Downes
Name/Title:	Authorized Signatory, Morgan Stanley Investment Management Inc.
Date:	02/12/2026

Exhibit Information

EXHIBIT NO. EXHIBITS ------------------ ------------------------------------ 99.1 Joint Filing Agreement 99.2 Item 7 Information * Attention. Intentional misstatements or omissions of fact constitute federal criminal violations (see 18 U.S.C. 1001).