Ultra Clean Holdings, Inc. revealed a major institutional ownership change in a September 13, 2026, SEC filing. The California State Teachers' Retirement System (CalSTRS) increased its stake in the semiconductor equipment firm by 14,062.1% during the second quarter.
The pension fund purchased 7,262,083 additional shares, bringing its total position to 7,313,726 shares. This transaction grants CalSTRS a 16.31% ownership stake in the company.
The total stake reached a valuation of over $1.04 billion at the end of the quarter. This significant investment signals strong institutional confidence in Ultra Clean’s future growth.