[Form 4] Cytek Biosciences, Inc. Insider Trading Activity

Rhea-AI Filing Summary

Richard Chin, a director of Cytek Biosciences, Inc. (CTKB), was awarded 4,071 restricted stock units (RSUs) that convert one-for-one into common shares. The RSUs were granted on 08/18/2025 and are reported as 4,071 shares beneficially owned following the award. The filing shows the award has a $0 exercise price because these are restricted stock units rather than paid stock options.

The RSUs vest on a staggered schedule: 2/36 of the total vests on 08/18/2025; 3/36 vests on 11/18/2025 and each November 18 thereafter; 3/36 vests on 03/10/2026 and each March 10 thereafter; 3/36 vests on 05/18/2026 and each May 18 thereafter; and 3/36 vests on 08/18/2026 and each August 18 thereafter until fully vested. The report was signed by an attorney-in-fact on 08/20/2025.

Positive

• Director alignment with shareholders: RSU grant ties director compensation to company equity value over time
• Standard time-based vesting: Vesting schedule promotes retention through August 2026

Negative

• Potential dilution: Shares will dilute existing shareholders as RSUs convert to common stock upon vesting
• Materiality unclear: Filing does not disclose CTKB's total outstanding shares or size of award relative to peer/board compensation

Insights

Securities Analyst

TL;DR: Director Richard Chin received 4,071 RSUs that vest over a multi-year schedule, modestly increasing his reported shareholding.

The grant of 4,071 restricted stock units to a board director is a routine equity-based compensation event that aligns the director with shareholder interests without immediate cash outlay by the recipient or the company. The award converts one-for-one into common stock and carries no exercise price, consistent with typical RSU awards. The vesting schedule is time-based and front-loaded with a small initial tranche (2/36) vesting immediately on grant date, then periodic vesting through August 2026. For investors, this is non-dilutive immediately but will dilute outstanding shares as units vest and shares are issued. The size of the award (4,071 shares) should be evaluated relative to CTKB’s total outstanding shares to assess materiality; the form does not provide that context. No cash transactions, sales, or exercised options are reported.

Corporate Governance Expert

TL;DR: This is a standard director compensation RSU grant with time-based vesting and no additional governance concerns disclosed.

The filing documents a standard practice of granting equity to directors to promote alignment with long-term shareholder value. Vesting terms use fractional monthly/periodic tranches through August 2026, which suggests retention intent. The filing indicates direct beneficial ownership following the grant and is filed singly by the reporting person. There are no indications of related-party transactions, acceleration triggers, or sales that would raise governance flags. Materiality is limited given the modest share count reported; however, the filing lacks disclosure of the total equity pool impact or relation to peer compensation levels.

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

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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^*

Chin Richard

(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)

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

3. Date of Earliest Transaction (Month/Day/Year)
08/18/2025

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	08/18/2025		M		4,071	A	(1)	4,071	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
Restricted Stock Units	(1)	08/18/2025		M			4,071	(2)	(2)	Common Stock	4,071	$0	69,218	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. 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-Fact	08/20/2025
	** Signature of Reporting Person	Date
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.
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FAQ

What did Richard Chin report on the Form 4 for CTKB?

He was granted 4,071 restricted stock units (RSUs) on 08/18/2025, which convert one-for-one into common shares.

How many shares does Richard Chin beneficially own after the reported transaction?

The filing reports 4,071 shares beneficially owned following the RSU award.

What is the vesting schedule for the RSUs reported in the CTKB Form 4?

2/36 vests on 08/18/2025; then 3/36 vests on 11/18/2025 and each November 18 thereafter; 3/36 vests on 03/10/2026 and each March 10 thereafter; 3/36 vests on 05/18/2026 and each May 18 thereafter; and 3/36 vests on 08/18/2026 and each August 18 thereafter until fully vested.

Was there any purchase price for the RSUs in the Form 4?

No. The RSUs are reported with a $0 price since they are restricted stock units rather than options.

Who signed the Form 4 and when was it filed?

The filing was signed by Valerie Barnett, Attorney-in-Fact, on 08/20/2025.