Cytek Biosciences (CTKB) CLO receives new options, 226,453 RSUs and stock from vesting

Rhea-AI Filing Summary

Cytek Biosciences, Inc. Chief Legal Officer Valerie Barnett reported equity compensation and vesting activity. She received a stock option grant for 120,114 shares of common stock at an exercise price of $4.23 per share, vesting monthly over four years. She was also granted 226,453 restricted stock units (RSUs) that vest over four years on specified May, August, November, and March dates. On the same date, several earlier RSU awards vested, converting a total of 29,722 RSUs into common shares. Of these, 11,748 shares were withheld at $4.23 per share to cover tax obligations, and the remainder increased her directly held common stock to 134,436 shares. These are compensation-related grants, exercises, and tax withholdings rather than open‑market purchases or sales.

Insights

Equity compensation analyst

Routine equity grants and RSU vesting for Cytek’s Chief Legal Officer.

Cytek Biosciences granted Chief Legal Officer Valerie Barnett stock options for 120,114 shares at an exercise price of $4.23, plus 226,453 new RSUs. These awards vest over four years on a detailed monthly and annual schedule.

Separately, previously granted RSUs vested, converting 29,722 units into common stock. To satisfy tax obligations, 11,748 shares were withheld at $4.23 per share, with the balance added to her direct common stock holdings, which now total 134,436 shares.

The transactions are compensation-related grants, vesting events, and associated tax withholding, not open‑market buying or selling. They primarily update Barnett’s equity position and reflect ongoing long‑term incentive structures rather than a directional view on Cytek Biosciences, Inc. stock.

SEC Form 4

FORM 4

UNITED 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

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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^*

Barnett Valerie

(Last) (First) (Middle)

C/O CYTEK BIOSCIENCES, INC.

47215 LAKEVIEW BOULEVARD

(Street)

FREMONT CA 94538

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Cytek Biosciences, Inc. [ CTKB ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	CHIEF LEGAL OFFICER

3. Date of Earliest Transaction (Month/Day/Year)
03/10/2026

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

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)
			Code	V	Amount	(A) or (D)	Price
Common Stock	03/10/2026		M		4,908	A	(1)	121,370	D
Common Stock	03/10/2026		F		1,761(2)	D	$4.23	119,609	D
Common Stock	03/10/2026		M		10,313	A	(1)	129,922	D
Common Stock	03/10/2026		F		4,247(2)	D	$4.23	125,675	D
Common Stock	03/10/2026		M		14,501	A	(1)	140,176	D
Common Stock	03/10/2026		F		5,740(2)	D	$4.23	134,436	D

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)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Employee Stock Option (right to buy)	$4.23	03/10/2026		A		120,114		(3)	03/09/2036	Common Stock	120,114	$0	120,114	D
Restricted Stock Units	(1)	03/10/2026		A		226,453		(4)	(4)	Common Stock	226,453	$0	226,453	D
Restricted Stock Units	(1)	03/10/2026		M			4,908	(5)	(5)	Common Stock	4,908	$0	14,734	D
Restricted Stock Units	(1)	03/10/2026		M			10,313	(6)	(6)	Common Stock	10,313	$0	61,884	D
Restricted Stock Units	(1)	03/10/2026		M			14,501	(7)	(7)	Common Stock	14,501	$0	130,512	D

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. Represents the number of shares withheld by and surrendered to the Issuer on March 10, 2026, to satisfy tax withholding obligations that arose in connection with the vesting of the RSU Award.

3. The shares subject to the stock option shall vest over 4 years with 1/48 of the total shares underlying the stock option vesting on April 10, 2026 and each month thereafter until fully vested.

4. 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, 2026 and each May 18 thereafter; 3/48 of the total shares underlying the RSU Award vesting August 18, 2026 and each August 18 thereafter; 3/48 of the total shares underlying the RSU Award vesting November 18, 2026 and each November 18 thereafter; and 4/48 of the total shares underlying the RSU Award vesting on March 10, 2027 and each March 10 thereafter, until fully vested.

5. 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.

6. 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.

7. 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 each March 10, 2026 and each March 10 thereafter, until fully vested.

	/s/ Valerie Barnett	03/12/2026
	** Signature of Reporting Person	Date
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FAQ

What equity awards did Cytek Biosciences (CTKB) grant to its Chief Legal Officer?

Cytek Biosciences granted Chief Legal Officer Valerie Barnett stock options for 120,114 shares at an exercise price of $4.23 and 226,453 restricted stock units. Both awards vest over four years, following specified monthly and annual vesting schedules described in the filing’s footnotes.

How many Cytek Biosciences (CTKB) RSUs vested for Valerie Barnett in this Form 4?

The Form 4 shows that a total of 29,722 previously granted restricted stock units vested and converted into common shares. These vested RSUs came from multiple multi‑year award schedules that release portions of the shares on May 18, August 18, November 18 and March 10 each year.

Were any Cytek Biosciences (CTKB) shares sold on the market in this Form 4?

No open‑market sales are reported. The only share disposals are Form F transactions, where 11,748 shares were withheld and surrendered to Cytek Biosciences at $4.23 per share solely to cover tax withholding obligations arising from RSU vesting on March 10, 2026.

What is Valerie Barnett’s Cytek Biosciences (CTKB) common stock holding after these transactions?

After the grants, RSU conversions, and tax‑withholding dispositions, Valerie Barnett directly holds 134,436 shares of Cytek Biosciences common stock. This figure reflects her updated ownership position following the March 10, 2026 equity compensation and vesting activities reported in the Form 4.

What are the vesting terms of Valerie Barnett’s new Cytek Biosciences stock option grant?

The 120,114‑share stock option vests over four years, with 1/48 of the underlying shares vesting on April 10, 2026 and an additional 1/48 vesting each month thereafter until fully vested. This structure encourages long‑term retention and alignment with Cytek Biosciences’ performance.

How do the new Cytek Biosciences (CTKB) RSU awards for Valerie Barnett vest over time?

The 226,453 RSUs vest over four years in an uneven schedule: 2/48 of the shares vest each May 18, 3/48 each August 18, 3/48 each November 18, and 4/48 each March 10. These installments repeat annually until the entire RSU award is fully vested.