Richard Chin - 18 May 2026 Form 4 Insider Report for Cytek Biosciences, Inc. (CTKB)

Reporting relationship: Director
Issuer ticker: CTKB
Reported as of: 18 May 2026
Net transaction value: $0
SEC form: 4
Accepted by SEC: 20 May 2026, 17:59:27 UTC
Prior SEC filing: 12 Mar 2026
Next SEC filing: 12 Jun 2026
Source filing: View source filing
Reporting owner signature: /s/ Valerie Barnett, Attorney-in-Fact

Key filing fact

Richard Chin filed Form 4 for Cytek Biosciences, Inc. (CTKB) on 20 May 2026.

Key facts

This page summarizes Richard Chin's Form 4 filing for Cytek Biosciences, Inc. (CTKB).
2 reported transactions and 1 derivative row are listed below.
Accepted by SEC: 20 May 2026, 17:59.

Change

Previous filing in this sequence was filed on 12 Mar 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 0001337252 Primary reporting owner

Chin Richard

Relationship: Director
Address: C/O CYTEK BIOSCIENCES, INC., 47215 LAKEVIEW BOULEVARD, FREMONT
Signature: /s/ Valerie Barnett, Attorney-in-Fact
Signature date: 20 May 2026

Reported non-derivative transactions

Shares, units, or other non-derivative securities reported in this filing.

CTKB transaction

Common Stock

Options Exercise

Transaction value
Shares: +6,107
Change %: +38%
Price
Shares after: 22,392
Date: 18 May 2026
Ownership: Direct
Footnotes: F1

Reported derivative securities

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

CTKB transaction Derivative

Restricted Stock Units

Options Exercise

Transaction value
Shares: -6,107
Change %: -11%
Price: $0.000000^*
Shares after: 50,897
Date: 18 May 2026
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 6,107
Exercise price
Footnotes: F1, F2

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

Additional SEC filing notes

Filing notes and footnotes

Explanation of responses 2 footnotes

Footnote F1

Each Restricted Stock Unit (the "RSU Award") represents a contingent right to receive one share of the Issuer's common stock.

Footnote F2

2/36 of the total shares subject to the RSU Award shall vest on August 18, 2025; 3/36 of the total shares subject to the RSU Award shall vest on November 18, 2025 and each November 18 thereafter; 3/36 of the total shares underlying the RSU Award shall vest on March 10, 2026 and each March 10 thereafter; 3/36 of the total shares underlying the RSU Award vesting shall vest on May 18, 2026 and each May 18 thereafter; and 3/36 of the total shares underlying the RSU Award shall vest on August 18, 2026 and each August 18 thereafter, until fully vested.