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Cytek Biosciences (CTKB) director converts 6,107 RSUs to common stock

Filing Impact
(Neutral)
Filing Sentiment
(Neutral)
Form Type
4

Rhea-AI Filing Summary

Cytek Biosciences, Inc. director Richard Chin reported a routine equity compensation event. On May 18, 2026, he exercised 6,107 Restricted Stock Units, receiving the same number of shares of common stock at a stated price of $0.00 per share.

Following the transaction, Chin directly holds 22,392 shares of Cytek common stock and 50,897 Restricted Stock Units. The RSU Award represents the right to receive one share of common stock per unit and is scheduled to vest in multiple tranches between August 18, 2025 and August 18, 2026.

Positive

  • None.

Negative

  • None.
Insider Chin Richard
Role null
Type Security Shares Price Value
Exercise Restricted Stock Units 6,107 $0.00 --
Exercise Common Stock 6,107 $0.00 --
Holdings After Transaction: Restricted Stock Units — 50,897 shares (Direct, null); Common Stock — 22,392 shares (Direct, null)
Footnotes (1)
  1. Each Restricted Stock Unit (the "RSU Award") represents a contingent right to receive one share of the Issuer's common stock. 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.
RSUs exercised 6,107 units Restricted Stock Units converted to common stock on May 18, 2026
Shares received 6,107 shares Common stock issued from RSU exercise at $0.00 per share
Common shares held 22,392 shares Direct holdings after the reported transaction
RSUs remaining 50,897 units Restricted Stock Units directly held after the transaction
Restricted Stock Units financial
"The RSU Award represents a contingent right to receive one share of the Issuer's common stock."
Restricted stock units are a type of company reward where employees are promised shares of stock, but they only fully own these shares after meeting certain conditions, like staying with the company for a set time. They matter because they can become valuable assets and are often used to motivate employees to help the company succeed.
RSU Award financial
"Each Restricted Stock Unit (the "RSU Award") represents a contingent right to receive one share"
vesting financial
"shares subject to the RSU Award shall vest on August 18, 2025; 3/36 of the total shares subject"
Vesting is the process by which you earn full ownership of something, like company stock or a retirement benefit, over time. It’s like earning the right to keep a gift piece by piece the longer you stay with a company, making sure employees stay committed before they receive all the benefits.
derivative exercise/conversion financial
"transaction_action": "derivative exercise/conversion""
Common Stock financial
"underlying_security_title": "Common Stock""
Common stock represents ownership shares in a company, giving investors a stake in its success and a say in important decisions through voting rights. It is the most common type of stock traded on markets and can provide income through dividends, as well as potential for value growth. For investors, holding common stock means sharing in the company’s profits and risks.
Form 4 Insider Transactions: What Each Field Means →
SEC Form 4
FORM 4UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940
OMB APPROVAL
OMB Number:3235-0287
Estimated average burden
hours per response:0.5
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.
1. Name and Address of Reporting Person*
Chin Richard
(Last)(First)(Middle)
C/O CYTEK BIOSCIENCES, INC.
47215 LAKEVIEW BOULEVARD
(Street)
FREMONT CALIFORNIA 94538
(City)(State)(Zip)
UNITED STATES
(Country)		2. Issuer Name and Ticker or Trading Symbol
Cytek Biosciences, Inc. [ CTKB ] 		5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
XDirector10% Owner
Officer (give title below)Other (specify below)
2a. Foreign Trading Symbol
3. Date of Earliest Transaction (Month/Day/Year)
05/18/2026		6. Individual or Joint/Group Filing (Check Applicable Line)
XForm filed by One Reporting Person
Form filed by More than One Reporting Person
4. If Amendment, Date of Original Filed (Month/Day/Year)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year)2A. Deemed Execution Date, if any (Month/Day/Year)3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4)
CodeVAmount(A) or (D)Price
Common Stock05/18/2026M6,107A(1)22,392D
Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year)3A. Deemed Execution Date, if any (Month/Day/Year)4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 6. Date Exercisable and Expiration Date (Month/Day/Year)7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4)
CodeV(A)(D)Date ExercisableExpiration DateTitleAmount or Number of Shares
Restricted Stock Units(1)05/18/2026M6,107 (2) (2)Common Stock6,107$050,897D
Explanation of Responses:
1. Each Restricted Stock Unit (the "RSU Award") represents a contingent right to receive one share of the Issuer's common stock.
2. 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.
/s/ Valerie Barnett, Attorney-in-Fact05/20/2026
** Signature of Reporting PersonDate
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.
* Form 4: SEC 1474 (03-26)

Source: View Original Filing on SEC EDGAR

FAQ

What insider transaction did Cytek Biosciences (CTKB) report for Richard Chin?

Cytek Biosciences director Richard Chin exercised 6,107 Restricted Stock Units, receiving 6,107 shares of common stock at a stated price of $0.00 per share. This is a derivative exercise, not an open-market stock purchase or sale.

How many Cytek Biosciences (CTKB) shares does Richard Chin hold after this Form 4?

After the reported transaction, Richard Chin directly holds 22,392 shares of Cytek Biosciences common stock. In addition, he holds 50,897 Restricted Stock Units, each representing a contingent right to receive one share of common stock upon vesting.

What are Restricted Stock Units (RSUs) in the Cytek Biosciences (CTKB) Form 4?

In this filing, each Restricted Stock Unit represents a contingent right to receive one share of Cytek common stock. These RSUs vest over time according to a defined schedule and convert into common shares upon vesting and settlement.

What is the vesting schedule for Richard Chin’s RSU Award at Cytek Biosciences (CTKB)?

The RSU Award vests in tranches: portions vest on August 18, 2025, November 18, 2025 and each November 18 thereafter, March 10, 2026 and each March 10 thereafter, May 18, 2026 and each May 18 thereafter, and August 18, 2026 and each August 18 thereafter.

Was Richard Chin’s Cytek Biosciences (CTKB) transaction a stock sale?

No. The Form 4 shows a derivative exercise coded “M,” where 6,107 Restricted Stock Units were converted into 6,107 shares of common stock. There were no open-market sales or purchases reported in this filing.