SC 13G 1 frontier-uctt123123.htm

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION
Washington, DC 20549

SCHEDULE 13G

Under the Securities Exchange Act of 1934

(Amendment No. )*

Ultra Clean Holdings, Inc.

(Name of Issuer)

Common stock, par value $0.001 per share

(Title of Class of Securities)

90385V107

(CUSIP Number)

December 31, 2023

(Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

x Rule 13d-1(b)

o Rule 13d-1(c)

o Rule 13d-1(d)

*The remainder of this cover page shall be filled out for a reporting person’s initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter the disclosures provided in a prior cover page.

The information required in 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).

CUSIP No.  90385V107

SCHEDULE 13G

Page 2 of 6 Pages

1

NAME OF REPORTING PERSONS

FRONTIER CAPITAL MANAGEMENT CO., LLC.

2

CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP

(a) o

(b) o

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

1,170,285

6

SHARED VOTING POWER

0

7

SOLE DISPOSITIVE POWER

2,559,943

8

SHARED DISPOSITIVE POWER

0

9

AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

2,559,943

10

CHECK IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES

o

11

PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

5.71%

12

TYPE OF REPORTING PERSON

IA

CUSIP No. 90385V107

SCHEDULE 13G

Page 3 of 6 Pages

Item 1. (a) Name of Issuer

Ultra Clean Holdings, Inc.

Item 1. (b) Address of Issuer’s Principal Executive Offices

26462 Corporate Avenue

Hayward, California 94545

Item 2. (a) Name of Person Filing

FRONTIER CAPITAL MANAGEMENT CO., LLC

(b) Address of Principal Business Office, or, if none, Residence

99 Summer Street

Boston, MA 02110

(c) Citizenship

Delaware

Item 2. (d) Title of Class of Securities

Common stock, par value $0.001 per share (the “Common Stock”)

Item 2. (e) CUSIP No.:

90385V107

CUSIP No.  90385V107

SCHEDULE 13G

Page 4 of 6 Pages

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) x 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);

(k) ¨ A group, in accordance with §240.13d-1(b)(1)(ii)(K). If filing as a non-U.S. institution in accordance with §240.13d-1(b)(1)(ii)(J), please specify the type of institution:

CUSIP No. 90385V107

SCHEDULE 13G

Page 5 of 6 Pages

Item 4. Ownership

Provide the following information regarding the aggregate number and percentage of the class of securities of the issuer identified in Item 1.

(a) Amount beneficially owned: 2,559,943

(b) Percent of class: 5.71%

(c) Number of shares as to which the person has:

(i) Sole power to vote or to direct the vote: 1,170,285

(ii) Shared power to vote or to direct the vote: 0

(iii) Sole power to dispose or to direct the disposition of: 2,559,943

(iv) Shared power to dispose or to direct the disposition of: 0

Item 5. Ownership of Five Percent or Less of a Class

If this statement is being filed to report the fact that as of the date hereof the reporting person has ceased to be the beneficial owner of more than five percent of the class of securities, check the following [ ].

Item 6. Ownership of More Than Five 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. Certification

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.

CUSIP No.  90385V107

SCHEDULE 13G

Page 6 of 6 Pages

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.

Dated: February 14, 2024

FRONTIER CAPITAL MANAGEMENT CO., LLC.

By: /s/ Robert E. Phay

Robert E. Phay, Chief Compliance Officer & General Counsel


1	NAME OF REPORTING PERSONS FRONTIER CAPITAL MANAGEMENT CO., LLC.
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) o (b) o
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 1,170,285
		6	SHARED VOTING POWER 0
		7	SOLE DISPOSITIVE POWER 2,559,943
		8	SHARED DISPOSITIVE POWER 0
9	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 2,559,943
10	CHECK IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES			o
11	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) 5.71%
12	TYPE OF REPORTING PERSON IA

(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)	x	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);

(k)	¨	A group, in accordance with §240.13d-1(b)(1)(ii)(K). If filing as a non-U.S. institution in accordance with §240.13d-1(b)(1)(ii)(J), please specify the type of institution:


	FRONTIER CAPITAL MANAGEMENT CO., LLC.

	By:	/s/ Robert E. Phay
		Robert E. Phay, Chief Compliance Officer & General Counsel

SEC Form SC 13G filed by Ultra Clean Holdings Inc.