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uctt-20251023false000127501400012750142025-04-282025-04-28

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): October 23, 2025

Ultra Clean Holdings, Inc. (Exact name of Registrant as Specified in Its Charter)

Delaware000-5064661-1430858 (State or Other Jurisdiction of Incorporation)(Commission File Number)(IRS Employer Identification No.)

26462 Corporate Avenue Hayward, California

94545 (Address of Principal Executive Offices)(Zip Code)

Registrant’s Telephone Number, Including Area Code: 510 576-4400

N/A

(Former Name or Former Address, if Changed Since Last Report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions: ☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c)) Securities registered pursuant to Section 12(b) of the Act:

Title of each classTrading Symbol(s) Name of each exchange on which registered Common Stock, $0.001 par valueUCTTThe Nasdaq Global Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§ 230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§ 240.12b-2 of this chapter). Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 2.02 Results of Operations and Financial Condition. On October 28, 2025, Ultra Clean Holdings, Inc. (“UCT,” the “Company” or “We”) issued a press release announcing its financial results for its third fiscal quarter September 26, 2025. A copy of the Company’s press release is attached hereto as Exhibit 99.1. The information furnished under Item 2.02 of this Current Report on Form 8-K, including the exhibit, shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), nor shall it be deemed incorporated by reference into the Company’s filings with the SEC under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such a filing. Item 8.01 Other Events On October 23, 2025, the Board of Directors approved a share repurchase program authorizing the Company to purchase up to an aggregate of $150 million of the Company’s common stock over a three-year period. Subject to applicable laws and regulations, the shares may be purchased from time to time in the open market, in privately negotiated transactions or by other means, including through the use of any trading plans designed to qualify under Rule 10b5-1 under the Securities Exchange Act of 1934. Such purchases will be at times and in amounts as the Company deems appropriate, based on factors such as market conditions, legal and regulatory requirements and other business considerations. Item 9.01 Financial Statements and Exhibits. (d) Exhibits

ExhibitExhibit Description 99.1Press Release dated October 28, 2025

104Cover Page Interactive Data File (embedded within the Inline XBRL document)

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized.

ULTRA CLEAN HOLDINGS, INC.

Date:October 28, 2025 By:/s/ Paul Y. Cho Name: Paul Y. Cho Title: General Counsel and Corporate Secretary

uctt-20250728false000127501400012750142025-04-282025-04-28

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): July 28, 2025

Ultra Clean Holdings, Inc. (Exact name of Registrant as Specified in Its Charter)

Delaware000-5064661-1430858 (State or Other Jurisdiction of Incorporation)(Commission File Number)(IRS Employer Identification No.)

26462 Corporate Avenue Hayward, California

94545 (Address of Principal Executive Offices)(Zip Code)

Registrant’s Telephone Number, Including Area Code: 510 576-4400

N/A

(Former Name or Former Address, if Changed Since Last Report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions: ☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c)) Securities registered pursuant to Section 12(b) of the Act:

Title of each classTrading Symbol(s) Name of each exchange on which registered Common Stock, $0.001 par valueUCTTThe Nasdaq Global Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§ 230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§ 240.12b-2 of this chapter). Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 2.02 Results of Operations and Financial Condition. On July 28, 2025, Ultra Clean Holdings, Inc. (“UCT,” the “Company” or “We”) issued a press release announcing its financial results for its second fiscal quarter June 27, 2025. A copy of the Company’s press release is attached hereto as Exhibit 99.1. The information furnished under Item 2.02 of this Current Report on Form 8-K, including the exhibit, shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), nor shall it be deemed incorporated by reference into the Company’s filings with the SEC under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such a filing. Item 9.01 Financial Statements and Exhibits. (d) Exhibits

ExhibitExhibit Description 99.1Press Release dated July 28, 2025

104Cover Page Interactive Data File (embedded within the Inline XBRL document)

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized.

ULTRA CLEAN HOLDINGS, INC.

Date:July 28, 2025 By:/s/ Paul Y. Cho Name: Paul Y. Cho Title: General Counsel and Corporate Secretary