Wenbin Jiang - 18 Nov 2025 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
18 Nov 2025
Net transactions value
-$151,555
Form type
4
Filing time
20 Nov 2025, 18:56:59 UTC
Previous filing
20 Aug 2025
Next 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 20 Nov 2025 0001872873

Transactions Table

Type Sym Class Transaction Value $ Shares Change % * Price $ Shares After Date Ownership Footnotes
transaction CTKB Common Stock Options Exercise +6,758 +0.13% 5,321,175 18 Nov 2025 Direct F1
transaction CTKB Common Stock Tax liability $14,710 -2,660 -0.05% $5.53 5,318,515 18 Nov 2025 Direct F2
transaction CTKB Common Stock Options Exercise +11,781 +0.22% 5,330,296 18 Nov 2025 Direct F1
transaction CTKB Common Stock Tax liability $25,637 -4,636 -0.09% $5.53 5,325,660 18 Nov 2025 Direct F2
transaction CTKB Common Stock Options Exercise +22,100 +0.41% 5,347,760 18 Nov 2025 Direct F1
transaction CTKB Common Stock Tax liability $48,094 -8,697 -0.16% $5.53 5,339,063 18 Nov 2025 Direct F2
transaction CTKB Common Stock Options Exercise +29,002 +0.54% 5,368,065 18 Nov 2025 Direct F1
transaction CTKB Common Stock Tax liability $63,114 -11,413 -0.21% $5.53 5,356,652 18 Nov 2025 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 Restricted Stock Units Options Exercise $0 -6,758 -60% $0.000000 4,514 18 Nov 2025 Common Stock 6,758 Direct F1, F3
transaction CTKB Restricted Stock Units Options Exercise $0 -11,781 -16% $0.000000 62,837 18 Nov 2025 Common Stock 11,781 Direct F1, F4
transaction CTKB Restricted Stock Units Options Exercise $0 -22,100 -9.7% $0.000000 206,273 18 Nov 2025 Common Stock 22,100 Direct F1, F5
transaction CTKB Restricted Stock Units Options Exercise $0 -29,002 -7% $0.000000 386,699 18 Nov 2025 Common Stock 29,002 Direct F1, F6
* 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 November 18, 2025, to satisfy tax withholding obligations that arose in connection with the vesting of the RSU Award.
F3 The shares subject to the RSU Award shall vest quarterly over four years, with 4/48th of the total shares underlying the RSU Award vesting on May 18, 2022 and 3/48th of the total shares underlying the RSU Award vesting each subsequent quarter thereafter on August 18, November 18, February 18 and May 18.
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, 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.
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, 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.
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, 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.