STOCK TITAN

Cytek Biosciences (CTKB) director adds 1,454 shares through RSU vesting

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

Rhea-AI Filing Summary

Cytek Biosciences director Michael Holder reported a routine equity compensation event. He acquired 1,454 shares of common stock on May 18, 2026 through the exercise or conversion of restricted stock units, with no open-market purchase or sale involved.

After this transaction, he directly holds 16,721 shares of common stock and 9,457 restricted stock units. The RSU award vests in multiple tranches between August 18, 2024 and August 18, 2025, gradually converting into common shares over time.

Positive

  • None.

Negative

  • None.
Insider Holder Michael
Role null
Type Security Shares Price Value
Exercise Restricted Stock Units 1,454 $0.00 --
Exercise Common Stock 1,454 $0.00 --
Holdings After Transaction: Restricted Stock Units — 9,457 shares (Direct, null); Common Stock — 16,721 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, 2024; 3/36 of the total shares subject to the RSU Award shall vest on November 18, 2024 and each November 18 thereafter; 4/36 of the total shares underlying the RSU Award shall vest on March 10, 2025 and each March 10 thereafter; 2/36 of the total shares underlying the RSU Award vesting shall vest on May 18, 2025 and each May 18 thereafter; and 3/36 of the total shares underlying the RSU Award shall vest on August 18, 2025 and each August 18 thereafter, until fully vested.
Common shares acquired 1,454 shares Common Stock from RSU exercise on May 18, 2026
Common shares held after 16,721 shares Total direct common stock holdings following transaction
RSUs converted 1,454 units Restricted Stock Units exercised into common stock on May 18, 2026
RSUs remaining 9,457 units Restricted Stock Units held after the transaction
Exercise price per share $0.00 per unit Reported transaction and conversion price for RSU exercise
Restricted Stock Units financial
"security_title": "Restricted Stock Units""
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"
derivative security financial
"transaction_code_description": "Exercise or conversion of derivative security""
A derivative security is a financial contract whose value comes from the price or performance of something else, such as a stock, bond, commodity, or market index. For investors it acts like an insurance policy or a wager: it can be used to protect against losses, lock in prices, or amplify gains and losses, so it can change a portfolio’s risk and potential return without owning the underlying asset directly.
vest financial
"shares subject to the RSU Award shall vest on August 18, 2024"
A vest is the process by which an employee earns the right to receive certain benefits or ownership interests, such as stock or retirement funds, over time. It’s similar to earning a reward gradually, ensuring that the benefit becomes fully yours only after a set period or meeting specific conditions. This makes it important for investors because it determines when they can actually claim or use those benefits.
contingent right financial
"represents a contingent right to receive one share of the Issuer's common stock"
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*
Holder Michael

(Last)(First)(Middle)
C/O CYTEK BIOSCIENCES, INC.
47215 LAKEVIEW BLVD.

(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 Stock05/18/2026M1,454A(1)16,721D
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)05/18/2026M1,454 (2) (2)Common Stock1,454$09,457D
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, 2024; 3/36 of the total shares subject to the RSU Award shall vest on November 18, 2024 and each November 18 thereafter; 4/36 of the total shares underlying the RSU Award shall vest on March 10, 2025 and each March 10 thereafter; 2/36 of the total shares underlying the RSU Award vesting shall vest on May 18, 2025 and each May 18 thereafter; and 3/36 of the total shares underlying the RSU Award shall vest on August 18, 2025 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)

FAQ

What insider transaction did Cytek Biosciences (CTKB) director Michael Holder report?

Director Michael Holder reported acquiring 1,454 Cytek Biosciences common shares through the exercise or conversion of restricted stock units. This was a compensation-related equity event rather than an open-market purchase or sale of existing shares.

How many Cytek Biosciences (CTKB) shares does Michael Holder hold after this Form 4?

After the reported transaction, Michael Holder directly holds 16,721 shares of Cytek Biosciences common stock. He also retains 9,457 restricted stock units, which represent additional shares that may be delivered as they vest over time.

Was Michael Holder’s Cytek Biosciences (CTKB) transaction an open-market buy or sell?

The transaction was not an open-market buy or sell. It reflects the exercise or conversion of 1,454 restricted stock units into common shares, a routine compensation-related equity event with no reported market purchase price or sale proceeds.

What are the key terms of Michael Holder’s RSU award at Cytek Biosciences (CTKB)?

Each restricted stock unit represents a contingent right to receive one Cytek Biosciences common share. The award vests in scheduled tranches on specific dates between August 18, 2024 and August 18, 2025, until the entire grant is fully vested.

Does Michael Holder still have unvested equity at Cytek Biosciences (CTKB) after this transaction?

Yes. Following the conversion of 1,454 RSUs into common stock, Michael Holder still holds 9,457 restricted stock units. These remaining RSUs are expected to vest in future scheduled tranches according to the award’s vesting schedule.