Frontier Capital discloses 7.73% Ultra Clean (UCTT) ownership stake

Rhea-AI Filing Summary

Frontier Capital Management Co., LLC has filed a beneficial ownership report on Ultra Clean Holdings, Inc., disclosing ownership of 3,509,839 shares of common stock, representing 7.73% of the company’s outstanding common shares as of the reported date.

Frontier Capital reports sole voting power over 2,078,342 shares and sole dispositive power over the full 3,509,839 shares, with no shared voting or dispositive authority. The firm certifies that the securities were acquired and are held in the ordinary course of business and not for the purpose of changing or influencing control of Ultra Clean Holdings.

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

Ultra Clean Holdings, Inc.

(Name of Issuer)

Common stock, par value $0.001 per share

(Title of Class of Securities)

90385V107

(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. 90385V107

1

Names of Reporting Persons

FRONTIER CAPITAL MANAGEMENT CO.,LLC

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 2,078,342.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 3,509,839.00
8	Shared Dispositive Power 0.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

3,509,839.00

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)

7.73 %

12

Type of Reporting Person (See Instructions)

IA

SCHEDULE 13G

Item 1.
(a)	Name of issuer: Ultra Clean Holdings, Inc.
(b)	Address of issuer's principal executive offices: 26462 Corporate Avenue Hayward, CA 94545
Item 2.
(a)	Name of person filing: FRONTIER CAPITAL MANAGEMENT CO., LLC
(b)	Address or principal business office or, if none, residence: 99 Summer Street Boston, MA 02110
(c)	Citizenship: Delaware
(d)	Title of class of securities: Common stock, par value $0.001 per share
(e)	CUSIP No.: 90385V107
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: 3,509,839
(b)	Percent of class: 7.73%
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: 2,078,342
	(ii) Shared power to vote or to direct the vote: 0
	(iii) Sole power to dispose or to direct the disposition of: 3,509,839
	(iv) Shared power to dispose or to direct the disposition of: 0
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.
	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 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.

FRONTIER CAPITAL MANAGEMENT CO.,LLC

Signature:	Robert E. Phay
Name/Title:	Robert E. Phay, Chief Compliance Officer & General Counsel
Date:	02/17/2026

FAQ

What stake does Frontier Capital hold in Ultra Clean Holdings (UCTT)?

Frontier Capital Management Co., LLC reports beneficial ownership of 3,509,839 Ultra Clean Holdings common shares, representing 7.73% of the outstanding class. This makes Frontier a significant institutional holder under SEC rules that require disclosure above the 5% ownership threshold.

How much voting power does Frontier Capital have in UCTT shares?

Frontier Capital has sole voting power over 2,078,342 Ultra Clean Holdings common shares. It reports no shared voting authority, meaning all reported voting rights are controlled directly by Frontier Capital according to the Schedule 13G ownership disclosure language provided.

Does Frontier Capital share dispositive power over UCTT stock?

Frontier Capital reports sole dispositive power over 3,509,839 Ultra Clean Holdings common shares and zero shared dispositive power. Sole dispositive power means Frontier alone decides whether and how to sell or otherwise dispose of these securities, based on the filing’s ownership breakdown.

Why is Frontier Capital’s Ultra Clean Holdings (UCTT) position disclosed?

The position is disclosed because Frontier Capital’s beneficial ownership exceeds 5% of Ultra Clean Holdings’ common stock. SEC rules require institutional investors crossing this threshold to file a beneficial ownership report detailing share count, percentage of class, and voting and dispositive powers.

Is Frontier Capital’s UCTT investment intended to influence control of the company?

Frontier Capital certifies the Ultra Clean Holdings shares were acquired and are held in the ordinary course of business, not to change or influence control. It also states the holdings are not part of any transaction aimed at obtaining control of the issuer.

What type of securities does Frontier Capital own in Ultra Clean Holdings (UCTT)?

Frontier Capital’s disclosed holdings are Ultra Clean Holdings common stock with a par value of $0.001 per share, identified by CUSIP 90385V107. The filing specifies no other classes of securities, focusing solely on this common equity position and related ownership rights.