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Cytek Biosciences (CTKB) director exercises RSUs and receives new equity awards

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

Rhea-AI Filing Summary

Cytek Biosciences director Deborah J. Neff increased her equity stake through compensation-related transactions. On June 10, 2026, she exercised previously granted restricted stock units, receiving 43,973 shares of common stock and bringing her direct holdings to 59,679 shares.

On the same date, she received a director stock option for 18,261 shares of common stock at an exercise price of $4.05 per share, expiring on June 10, 2036. She was also granted 33,333 new restricted stock units, each representing one share of common stock, which are scheduled to vest on the earlier of June 10, 2027 or the company’s 2027 annual meeting of stockholders if held in June 2027.

Positive

  • None.

Negative

  • None.
Insider NEFF DEBORAH J
Role null
Type Security Shares Price Value
Grant/Award Restricted Stock Units 33,333 $0.00 --
Grant/Award Director Stock Option (right to buy) 18,261 $0.00 --
Exercise Restricted Stock Units 43,973 $0.00 --
Exercise Common Stock 43,973 $0.00 --
Holdings After Transaction: Restricted Stock Units — 33,333 shares (Direct, null); Director Stock Option (right to buy) — 18,261 shares (Direct, null); Common Stock — 59,679 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. 100% of the shares subject to the RSU Award shall vest on the earlier of June 10, 2027 and the date of the Issuer's 2027 annual meeting of stockholders (provided such meeting is held in June 2027). 100% of the shares subject to the option shall vest on the earlier of June 10, 2027 and the date of the Issuer's 2027 annual meeting of stockholders (provided such meeting is held in June 2027). 100% of the shares subject to the RSU Award vested on June 10, 2026.
RSUs converted to common stock 43,973 shares Restricted stock units exercised into common stock on June 10, 2026
Shares held after transactions 59,679 shares Common stock directly owned by Deborah J. Neff after June 10, 2026
Director stock option grant 18,261 options at $4.05 New option award with $4.05 exercise price, expiring June 10, 2036
New RSU grant 33,333 RSUs Restricted stock units granted June 10, 2026, vesting by June 10, 2027 or 2027 meeting
Option expiration date June 10, 2036 Expiration of director stock option award for 18,261 shares
Vesting date of prior RSU award June 10, 2026 100% vesting of 43,973-share RSU award delivering common stock
Restricted Stock Unit financial
"Each Restricted Stock Unit (the "RSU Award") represents a contingent right"
A restricted stock unit is a promise from a company to give an employee shares of stock after certain conditions are met, like staying with the company for a set amount of time. It’s like earning a bonus that turns into company stock once you’ve proven your commitment, making it a way to motivate and reward employees.
RSU Award financial
"Each Restricted Stock Unit (the "RSU Award") represents a contingent right"
Director Stock Option financial
"Director Stock Option (right to buy) with an exercise price of 4.0500"
exercise or conversion of derivative security financial
"transaction_code_description: Exercise or conversion of derivative security"
grant, award, or other acquisition financial
"transaction_code_description: Grant, award, or other acquisition"
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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*
NEFF DEBORAH J
(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)
06/10/2026		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 Stock06/10/2026M43,973A(1)59,679D
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)06/10/2026A33,333 (2) (2)Common Stock33,333$033,333D
Director Stock Option (right to buy)$4.0506/10/2026A18,261 (3)06/10/2036Common Stock18,261$018,261D
Restricted Stock Units(1)06/10/2026M43,973 (4) (4)Common Stock43,973$00D
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. 100% of the shares subject to the RSU Award shall vest on the earlier of June 10, 2027 and the date of the Issuer's 2027 annual meeting of stockholders (provided such meeting is held in June 2027).
3. 100% of the shares subject to the option shall vest on the earlier of June 10, 2027 and the date of the Issuer's 2027 annual meeting of stockholders (provided such meeting is held in June 2027).
4. 100% of the shares subject to the RSU Award vested on June 10, 2026.
/s/ Valerie Barnett, Attorney-in-Fact06/12/2026
** 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 transactions did Cytek Biosciences (CTKB) report for Deborah J. Neff?

Cytek Biosciences reported that director Deborah J. Neff exercised restricted stock units into 43,973 shares of common stock and received new equity awards, including stock options and additional restricted stock units, all dated June 10, 2026.

How many Cytek Biosciences (CTKB) shares does Deborah J. Neff hold after these transactions?

After exercising restricted stock units on June 10, 2026, Deborah J. Neff directly holds 59,679 shares of Cytek Biosciences common stock. This figure reflects her position following the receipt of 43,973 shares from the vested restricted stock unit award.

What stock option grant did Cytek Biosciences (CTKB) give director Deborah J. Neff?

Deborah J. Neff received a director stock option covering 18,261 shares of Cytek Biosciences common stock at an exercise price of $4.05 per share, expiring on June 10, 2036, providing long-dated equity compensation tied to the company’s future share performance.

What new restricted stock units did Cytek Biosciences (CTKB) grant to Deborah J. Neff?

Cytek Biosciences granted Deborah J. Neff 33,333 restricted stock units on June 10, 2026. Each unit represents one share of common stock and is scheduled to vest on the earlier of June 10, 2027 or the company’s 2027 annual shareholder meeting, if held in June 2027.

When did Deborah J. Neff’s prior Cytek Biosciences (CTKB) RSU award vest?

A prior restricted stock unit award to Deborah J. Neff, covering 43,973 shares of Cytek Biosciences common stock, vested 100% on June 10, 2026. That vesting triggered the delivery of 43,973 common shares, as reflected in the Form 4 filing.