Prothena (PRTA) awards CFO Nguyen Tran stock option on 230,000 shares

Rhea-AI Filing Summary

Nguyen Tran reported acquisition or exercise transactions in this Form 4 filing.

PROTHENA CORP PUBLIC LTD CO granted Nguyen Tran, its Chief Strategy Officer and CFO, a stock option covering 230,000 shares. The option vests as to 25% of the shares on March 3, 2027, with the remaining 75% vesting in equal monthly installments over the following three years, subject to continued employment.

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^*

Nguyen Tran

(Last) (First) (Middle)

C/O PROTHENA BIOSCIENCES INC

1800 SIERRA POINT PARKWAY

(Street)

BRISBANE CA 94005

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
PROTHENA CORP PUBLIC LTD CO [ PRTA ]

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

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	Chief Strategy Officer and CFO

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

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
Stock Option (Right to Buy)	$9.36	03/03/2026		A		230,000		(1)	03/03/2036	Ordinary Shares	230,000	$0	230,000	D

Explanation of Responses:

1. The shares subject to the option will vest and become exercisable as to 25% of the total number of shares subject to the option on March 3, 2027, and with respect to 1/48th of the total number of shares subject to the option in successive, equal monthly installments on each monthly anniversary thereafter, subject to the Reporting Person's continued employment with the Issuer on each such vesting date.

	/s/ Michael Malecek, as Attorney in Fact for Tran B. Nguyen	03/05/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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FAQ

What insider transaction did PROTHENA (PRTA) report for Nguyen Tran?

PROTHENA reported a grant of a stock option to Nguyen Tran covering 230,000 shares. This derivative award was recorded as an acquisition and reflects equity-based compensation tied to Mr. Tran’s ongoing role with the company.

Who is Nguyen Tran in relation to PROTHENA (PRTA)?

Nguyen Tran serves as PROTHENA’s Chief Strategy Officer and CFO. The Form 4 shows he received a stock option grant, aligning his compensation more closely with the company’s equity performance over a multi-year vesting period.

How many shares are covered by Nguyen Tran’s new stock option at PROTHENA (PRTA)?

The stock option granted to Nguyen Tran covers 230,000 shares. This entire amount is treated as directly owned derivative securities following the transaction, subject to the specified vesting schedule and his continued employment with PROTHENA.

What is the vesting schedule for Nguyen Tran’s PROTHENA (PRTA) stock option?

The option vests 25% of the total shares on March 3, 2027. The remaining 75% then vests in equal 1/48th monthly installments on each monthly anniversary thereafter, conditioned on Mr. Tran’s continued employment with PROTHENA on each vesting date.

Is the reported PROTHENA (PRTA) insider transaction a purchase or a grant?

The transaction is a grant of a stock option, classified as a “Grant, award, or other acquisition.” It represents an acquisition of derivative securities as part of compensation, rather than an open-market purchase of PROTHENA’s ordinary shares.

Does Nguyen Tran hold the PROTHENA (PRTA) option directly or indirectly?

The filing indicates the stock option is held with direct ownership. The ownership code is listed as “D” for direct, and there is no footnote shifting voting or investment authority to another entity such as a trust or partnership.