Ultra Clean Holdings, Inc.

9. STOCKHOLDERS’ EQUITY AND NONCONTROLLING INTERESTS

Treasury Stock

On October 20, 2022, 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 athree-year period.

No shares were repurchased under this program for the three months ended September 26, 2025, and for three and nine months ended September 27, 2024. For the nine months ended September 26, 2025, the Company repurchased approximately 0.2 million shares under this program for an aggregate cost of $3.4 million. All repurchases during the 2025 period occurred in the second quarter.

As of September 26, 2025,1.5 million shares had been repurchased under the program and they are held in treasury stock. The Company records treasury stock using the cost method. The Company may reissue these treasury shares as part of its stock-based compensation programs.

Non-controlling Interests

The Company owns part of the outstanding shares of Cinos Korea, a South Korean company that provides outsourced cleaning and recycling of precision parts for the semiconductor industry through its operating facilities in South Korea and through a partial interest in Cinos China.

The carrying value of the remaining interest held by another shareholder in Cinos Korea and the remaining interest in Cinos China are presented as noncontrolling interests in the accompanying Condensed Consolidated Financial Statements. Noncontrolling interests are calculated based on minority ownership percentages, representing the proportionate share of net assets in the balance sheet and net income (loss) in the income statement.