ProKidney CEO granted options on 3M shares

PROKIDNEY CORP. reported that Chief Executive Officer Bruce Culleton received a grant of employee stock options covering 3,000,000 shares of the company’s stock.

Rhea-AI Filing Summary

PROKIDNEY CORP. reported that Chief Executive Officer Bruce Culleton received a grant of employee stock options covering 3,000,000 shares of the company’s stock. These options were awarded as a derivative security with a reported price per share of $0.0000.

According to the filing, the option grant is scheduled to vest in substantially equal monthly installments over a four-year period beginning on March 1, 2026. This means the CEO’s right to exercise the options increases gradually each month over those four years.

Insider Trade Summary

Grant/Award: 3,000,000 shares

Grant/Award 1 txn

Insider Culleton Bruce

Role Chief Executive Officer

Type	Security	Shares	Price	Value
Grant/Award	Employee stock option (right to buy)	3,000,000	$0.00	$0.00

Holdings After Transaction: Employee stock option (right to buy) — 3,000,000 contracts (Direct)

Footnotes (1)

1. F1. The option vests in substantially equal monthly installments over the four year period beginning on March 1, 2026.

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

What insider transaction did PROKIDNEY CORP. (PROK) report for Bruce Culleton?

PROKIDNEY CORP. reported that CEO Bruce Culleton received a grant of employee stock options covering 3,000,000 shares. The options are classified as derivative securities and were reported with a price per share of $0.0000, reflecting an award rather than an open-market purchase or sale.

How many shares are covered by Bruce Culleton’s new stock option grant at PROKIDNEY (PROK)?

The new employee stock option grant to CEO Bruce Culleton covers 3,000,000 shares of PROKIDNEY CORP. common stock. After this grant, the Form 4 shows he directly holds options for 3,000,000 derivative securities related to the company’s shares, subject to the stated vesting schedule.

When do Bruce Culleton’s PROKIDNEY (PROK) stock options start vesting and over what period?

The stock options granted to CEO Bruce Culleton begin vesting on March 1, 2026. They vest in substantially equal monthly installments over a four-year period starting on that date, gradually increasing his exercisable option position each month throughout the vesting term.

Was Bruce Culleton’s PROKIDNEY (PROK) stock option grant an open-market buy or sell?

The transaction is reported as a grant or award acquisition, not an open-market buy or sell. It is coded as an employee stock option (right to buy) with a transaction code “A,” reflecting compensation-related issuance rather than a market transaction involving existing shares.

What type of security did Bruce Culleton receive in the PROKIDNEY (PROK) Form 4 filing?

Bruce Culleton received an employee stock option, described as a right to buy PROKIDNEY CORP. shares. This is classified as a derivative security tied to the company’s common stock, with vesting over four years and 3,000,000 underlying shares reported following the transaction.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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Accepted by SEC EDGAR 03/03/2026 - 07:57 AM Learn about SEC filing dates

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

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^*

Culleton Bruce

(Last) (First) (Middle)

C/O PROKIDNEY CORP

2000 FRONTIS PLAZA BLVD, SUITE 250

(Street)

WINSTON SALEM NC 27103

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
PROKIDNEY CORP. [ PROK ]

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

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

3. Date of Earliest Transaction (Month/Day/Year)
03/01/2026

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

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)	$2.24	03/01/2026		A		3,000,000		(1)	03/01/2036	Class A Common Stock	3,000,000	$0	3,000,000	D

Explanation of Responses:

1. The option vests in substantially equal monthly installments over the four year period beginning on March 1, 2026.

	/s/ James Coulston, attorney in fact	03/03/2026
	** 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).
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