Christopher S. Cook

CIK: 0001927266

Transaction Breakdown

Open Market Buys (P)1 (7.1%)

High conviction signal

Open Market Sales (S)3 (21.4%)

Position reduction

Option Exercises (M)0 (0.0%)

Derivative conversions

Awards (A)3 (21.4%)

Compensation grants

Other (G, F, J, C, D, …)7 (50.0%)

Gifts, tax withholding, conversions, dispositions to the issuer and other codes

Companies & Roles (1)

UCTT

Ultra Clean Holdings, Inc.

Officer

Discretionary Trading P&L

Holdings

Transaction History (14 total)

UCTT
Ultra Clean Holdings, Inc.
Aug 31, 2026
Tax Payment(F)
Direct
12.5K shares at avg. $67.83$848K
UCTT
Ultra Clean Holdings, Inc.
May 22, 2026
Award(A)
Direct
13.2K shares-
UCTT
Ultra Clean Holdings, Inc.
May 4, 2026
Sale(S)
Direct
10.2K shares at avg. $73.89$757K
UCTT
Ultra Clean Holdings, Inc.
May 4, 2026
Sale(S)
Direct
1.2K shares at avg. $74.55$92K
UCTT
Ultra Clean Holdings, Inc.
Apr 30, 2026
Tax Payment(F)
Direct
4.2K shares at avg. $78.15$327K
UCTT
Ultra Clean Holdings, Inc.
Apr 30, 2026
Tax Payment(F)
Direct
1.9K shares at avg. $78.15$145K
UCTT
Ultra Clean Holdings, Inc.
Apr 30, 2026
Tax Payment(F)
Direct
3.2K shares at avg. $78.15$247K
UCTT
Ultra Clean Holdings, Inc.
Apr 30, 2026
Sale(S)
Direct
11.9K shares at avg. $75.31$896K
UCTI
Ultra Clean Holdings, Inc.
Aug 29, 2025
Award(A)
Direct
73.7K shares-
UCTT
Ultra Clean Holdings, Inc.
Apr 30, 2025
Tax Payment(F)
Direct
2.6K shares at avg. $18.71$48K
UCTT
Ultra Clean Holdings, Inc.
Apr 30, 2025
Tax Payment(F)
Direct
2.2K shares at avg. $18.71$42K
UCTT
Ultra Clean Holdings, Inc.
Apr 30, 2025
Tax Payment(F)
Direct
1.9K shares at avg. $18.71$35K
UCTT
Ultra Clean Holdings, Inc.
Apr 25, 2025
Award(A)
Direct
27.8K shares-
UCTT
Ultra Clean Holdings, Inc.
Mar 7, 2025
Purchase(P)
Indirect
4.1K shares at avg. $25.30$104K

		Type	Shares	Price		Ownership
Aug 31, 2026	UCTT Ultra Clean Holdings, Inc.	Tax Payment(F)	12,497	$67.83	$847,672	Direct
May 22, 2026	UCTT Ultra Clean Holdings, Inc.	Award(A)	13,196	-	$0	Direct
May 4, 2026	UCTT Ultra Clean Holdings, Inc.	Sale(S)	10,247	$73.89	$757,151	Direct
May 4, 2026	UCTT Ultra Clean Holdings, Inc.	Sale(S)	1,231	$74.55	$91,771	Direct
Apr 30, 2026	UCTT Ultra Clean Holdings, Inc.	Tax Payment(F)	4,181	$78.15	$326,745	Direct
Apr 30, 2026	UCTT Ultra Clean Holdings, Inc.	Tax Payment(F)	1,861	$78.15	$145,437	Direct
Apr 30, 2026	UCTT Ultra Clean Holdings, Inc.	Tax Payment(F)	3,165	$78.15	$247,345	Direct
Apr 30, 2026	UCTT Ultra Clean Holdings, Inc.	Sale(S)	11,903	$75.31	$896,415	Direct
Aug 29, 2025	UCTI Ultra Clean Holdings, Inc.	Award(A)	73,686	-	-	Direct
Apr 30, 2025	UCTT Ultra Clean Holdings, Inc.	Tax Payment(F)	2,550	$18.71	$47,711	Direct
Apr 30, 2025	UCTT Ultra Clean Holdings, Inc.	Tax Payment(F)	2,225	$18.71	$41,630	Direct
Apr 30, 2025	UCTT Ultra Clean Holdings, Inc.	Tax Payment(F)	1,855	$18.71	$34,707	Direct
Apr 25, 2025	UCTT Ultra Clean Holdings, Inc.	Award(A)	27,831	-	-	Direct
Mar 7, 2025	UCTT Ultra Clean Holdings, Inc.	Purchase(P)	4,100	$25.30	$103,710	Indirect

1-14 of 14 transactions

About Cook Christopher S

Cook Christopher S (SEC CIK 0001927266) files insider reports with the SEC as President, Products Division of Ultra Clean Holdings, Inc. (UCTT).

Signal8 holds 8 ownership filings by Cook Christopher S, all Form 4s, filed between Mar 11, 2025 and Sep 2, 2026. Those filings report 14 transactions, from Mar 7, 2025 to Aug 31, 2026. Signal8's Form 4 history starts in Sep 2024.

The business address on Cook Christopher S's filings is in HAYWARD, CA.

Recent filings by Cook Christopher S

Aug 31, 2026: Tax withholding of UCTT shares (Form 4, code F).
May 22, 2026: Grant or award of UCTT shares (Form 4, code A).
May 4, 2026: Open-market sales of UCTT shares (2 lines, Form 4, code S).
Apr 30, 2026: Tax withholdings of UCTT shares (3 lines, Form 4, code F).
Apr 30, 2026: Open-market sale of UCTT shares (Form 4, code S).

Other insiders filing for Ultra Clean Holdings, Inc. (UCTT)

Xiao Jinsong, Chief Executive Officer
DAVERN ALEXANDER M, Director
Keogh Michael Dennis, Chief Financial Officer
HARDING BRIAN E, Chief Accounting Officer
Savage Sheri, CFO
Cho Paul Yoonku, General Counsel and Secretary

How to read Form 4 transaction codes