Wenbin Jiang - 10 Mar 2026 Form 4 Insider Report for Cytek Biosciences, Inc. (CTKB)

Role: PRESIDENT AND CEO, Director
Signature: /s/ Valerie Barnett, Attorney-in-Fact
Issuer symbol: CTKB
Transactions as of: 10 Mar 2026
Net transactions value: $0
Form type: 4
Filing time: 12 Mar 2026, 16:38:19 UTC
Previous filing: 20 Feb 2026
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
Jiang Wenbin	PRESIDENT AND CEO, Director	C/O CYTEK BIOSCIENCES, INC., 47215 LAKEVIEW BOULEVARD, FREMONT	/s/ Valerie Barnett, Attorney-in-Fact	12 Mar 2026	0001872873

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	CTKB	Common Stock	Options Exercise		+15,708	+0.29%		5,375,535	10 Mar 2026	Direct	F1
transaction	CTKB	Common Stock	Tax liability		-3,825	-0.07%	$4.23^*	5,371,710	10 Mar 2026	Direct	F2
transaction	CTKB	Common Stock	Options Exercise		+29,467	+0.55%		5,401,177	10 Mar 2026	Direct	F1
transaction	CTKB	Common Stock	Tax liability		-7,747	-0.14%	$4.23^*	5,393,430	10 Mar 2026	Direct	F2
transaction	CTKB	Common Stock	Options Exercise		+38,669	+0.72%		5,432,099	10 Mar 2026	Direct	F1
transaction	CTKB	Common Stock	Tax liability		-9,416	-0.17%	$4.23^*	5,422,683	10 Mar 2026	Direct	F2

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
transaction	CTKB	Employee Stock Option (right to buy)	Award		+485,545		$0.000000^*	485,545	10 Mar 2026	Common Stock	485,545	$4.23	Direct	F3
transaction	CTKB	Restricted Stock Units	Award		+915,407		$0.000000^*	915,407	10 Mar 2026	Common Stock	915,407		Direct	F1, F4
transaction	CTKB	Restricted Stock Units	Options Exercise		-15,708	-25%	$0.000000^*	47,129	10 Mar 2026	Common Stock	15,708		Direct	F1, F5
transaction	CTKB	Restricted Stock Units	Options Exercise		-29,467	-14%	$0.000000^*	176,806	10 Mar 2026	Common Stock	29,467		Direct	F1, F6
transaction	CTKB	Restricted Stock Units	Options Exercise		-38,669	-10%	$0.000000^*	348,030	10 Mar 2026	Common Stock	38,669		Direct	F1, F7

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	Each Restricted Stock Unit (the "RSU Award") represents a contingent right to receive one share of the Issuer's common stock.
F2	Represents the number of shares withheld by and surrendered to the Issuer on March 10, 2026, to satisfy tax withholding obligations that arose in connection with the vesting of the RSU Award.
F3	The shares subject to the stock option shall vest over 4 years with 1/48 of the total shares underlying the stock option vesting on April 10, 2026 and each month thereafter until fully vested.
F4	The shares subject to the RSU Award shall vest over 4 years with 2/48 of the total shares underlying the RSU Award vesting on May 18, 2026 and each May 18 thereafter; 3/48 of the total shares underlying the RSU Award vesting August 18, 2026 and each August 18 thereafter; 3/48 of the total shares underlying the RSU Award vesting November 18, 2026 and each November 18 thereafter; and 4/48 of the total shares underlying the RSU Award vesting on March 10, 2027 and each March 10 thereafter, until fully vested.
F5	The shares subject to the RSU Award shall vest over 4 years with 2/48 of the total shares underlying the RSU Award vesting on May 18, 2023 and each May 18 thereafter; 3/48 of the total shares underlying the RSU Award vesting on August 18, 2023 and each August 18 thereafter; 3/48 of the total shares underlying the RSU Award vesting on November 18, 2023 and each November 18 thereafter; and 4/48 of the total shares underlying the RSU Award vesting on March 10, 2024 and each March 10 thereafter, until fully vested.
F6	The shares subject to the RSU Award shall vest over 4 years with 2/48 of the total shares underlying the RSU Award vesting on May 18, 2024 and each May 18 thereafter; 3/48 of the total shares underlying the RSU Award vesting on August 18, 2024 and each August 18 thereafter; 3/48 of the total shares underlying the RSU Award vesting on November 18, 2024 and each November 18 thereafter; and 4/48 of the total shares underlying the RSU Award vesting on March 10, 2025 and each March 10 thereafter.
F7	The shares subject to the RSU Award shall vest over 4 years with 2/48 of the total shares underlying the RSU Award vesting on May 18, 2025 and each May 18 thereafter; 3/48 of the total shares underlying the RSU Award vesting on August 18, 2025 and each August 18 thereafter; 3/48 of the total shares underlying the RSU Award vesting on November 18, 2025 and each November 18 thereafter; and 4/48 of the total shares underlying the RSU Award vesting on March 10, 2026 and each March 10 thereafter, until fully vested.