Ilan Feuchtwang - 10 Aug 2026 Form 4 Insider Report for Cytek Biosciences, Inc. (CTKB)

Reporting relationship: Chief Legal Officer, Secretary
Issuer ticker: CTKB
Reported as of: 10 Aug 2026
Net transaction value: $0
SEC form: 4
Accepted by SEC: 12 Aug 2026, 18:31:21 UTC
Prior SEC filing: 30 Jun 2026
Source filing: View source filing
Reporting owner signature: /s/ Wenbin Jiang, Attorney-in-Fact

Key filing fact

Ilan Feuchtwang filed Form 4 for Cytek Biosciences, Inc. (CTKB) on 12 Aug 2026.

Key facts

This page summarizes Ilan Feuchtwang's Form 4 filing for Cytek Biosciences, Inc. (CTKB).
2 reported transactions and 2 derivative rows are listed below.
Accepted by SEC: 12 Aug 2026, 18:31.

Change

Previous filing in this sequence was filed on 30 Jun 2026.
Current net transaction value: $0.

Research use

This tells you what this filing adds before you inspect full transaction and derivative tables.
You can trace every row back to the original SEC filing document.

Evidence

Filed on Form 4

Ownership activity is grounded in SEC Form 4 disclosures.

View source filing

Reporting Owners (1)

CIK 0002141966 Primary reporting owner

Feuchtwang Ilan

Relationship: Chief Legal Officer, Secretary
Address: C/O CYTEK BIOSCIENCES, INC., 47215 LAKEVIEW BOULEVARD, FREMONT
Signature: /s/ Wenbin Jiang, Attorney-in-Fact
Signature date: 12 Aug 2026

Reported derivative securities

Options, warrants, convertible securities, or similar derivative positions disclosed in the filing.

CTKB transaction Derivative

Restricted Stock Units

Award

Transaction value
Shares: +241,416
Change %
Price: $0.000000^*
Shares after: 241,416
Date: 10 Aug 2026
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 241,416
Exercise price
Footnotes: F1, F2

CTKB transaction Derivative

Employee Stock Option (right to buy)

Award

Transaction value
Shares: +127,118
Change %
Price: $0.000000^*
Shares after: 127,118
Date: 10 Aug 2026
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 127,118
Exercise price: $4.66
Footnotes: F3

^* marks a reported price that did not pass the local price check.

Additional SEC filing notes

Filing notes and footnotes

Explanation of responses 3 footnotes

Footnote F1

Each restricted stock unit (the "RSU") represents a contingent right to receive one share of the Issuer's common stock.

Footnote F2

The RSUs shall vest and settle into common stock over 4 years, with 12/48 of the RSUs vesting on August 18, 2027; 3/48 of the RSUs vesting on November 18, 2027 and each November 18 thereafter; 4/48 of the RSUs vesting on March 10, 2028 and each March 10 thereafter; 2/48 of the RSUs vesting on May 18, 2028 and each May 18 thereafter; and 3/48 of the RSUs vesting on August 18, 2028 and each August 18 thereafter, until fully vested (in each case, subject to the Reporting Person's Continuous Service (as defined in the Issuer's 2021 Equity Invesntive Plan (the "2021 Plan"))).

Footnote F3

The shares subject to the option shall vest over 4 years with 25% vesting on August 10, 2027 and 1/48 of the shares vesting each month thereafter, until fully vested (in each case, subject to the Reporting Person's Continuous Service (as defined in the 2021 Plan)).