Prothena CSO converts 51,000 RSUs, disposes shares

Prothena Corp Public Ltd Co Chief Scientific Officer Wagner M. Zago exercised 51,000 restricted stock units into an equal number of ordinary shares on July 28, 2026.

Accepted by SEC EDGAR 07/30/2026 - 08:34 PM EDT Learn about SEC filing dates

Rhea-AI Filing Summary

Prothena Corp Public Ltd Co Chief Scientific Officer Wagner M. Zago exercised 51,000 restricted stock units into an equal number of ordinary shares on July 28, 2026. These units were part of an 85,000 RSU grant made on July 28, 2025. On the same date, he reported a transaction coded as a disposition to the issuer of 51,000 ordinary shares at $8.56 per share. Footnotes state that 34,000 RSUs from the 2025 grant remain subject to vesting.

Insider Trade Summary

51,000 shares exercised/converted

Exercise 3 txns

Insider Zago Wagner M.

Role Chief Scientific Officer

Type	Security	Shares	Price	Value
Exercise	Restricted Stock Units F2, F1, F3	51,000	$0.00	$0.00
Exercise	Ordinary Shares, par value $0.01 per share F1	51,000	--	--
Disposition	Ordinary Shares, par value $0.01 per share	51,000	$8.56	$437K

Holdings After Transaction: Restricted Stock Units — 0 contracts (Direct); Ordinary Shares, par value $0.01 per share — 34,000 shares (Direct)

Footnotes (3)

1. F1. Each restricted stock unit ("RSU") represents the contingent right to receive one share of the Issuer's Ordinary Shares upon vesting.
2. F2. These RSUs reported in Table II were granted to the Reporting Person on July 28, 2025 as part of an aggregate award of 85,000 RSUs and initially reported in Table I of the Form 4 filed on July 30, 2025, because they were solely settleable in shares at the time of grant. These RSUs are being moved to Table II as of this Form 4.
3. F3. These RSUs reported in Table II are fully vested as of July 28, 2026 (the one-year anniversary of the grant date). The remainder of the 85,000 RSUs reported in Table I (34,000 RSUs) are subject to vesting.

Key Figures

RSUs exercised: 51000.0000 units Disposition share count: 51000.0000 shares Disposition price: $8.5600 per share +2 more

5 metrics

RSUs exercised 51000.0000 units Restricted stock units converted into ordinary shares on July 28, 2026

Disposition share count 51000.0000 shares Ordinary shares reported as a disposition to the issuer at $8.56 per share

Disposition price $8.5600 per share Price for 51,000 ordinary shares disposed to the issuer

Original RSU grant size 85,000 RSUs RSUs granted to the reporting person on July 28, 2025

Unvested RSUs remaining 34,000 RSUs Portion of the 85,000-unit grant that remains subject to vesting

Key Terms

Restricted Stock Units, Ordinary Shares, Disposition to issuer, vesting

4 terms

Restricted Stock Units financial

"Each restricted stock unit ("RSU") represents the contingent right to receive one share"

Restricted stock units are a type of company reward where employees are promised shares of stock, but they only fully own these shares after meeting certain conditions, like staying with the company for a set time. They matter because they can become valuable assets and are often used to motivate employees to help the company succeed.

Ordinary Shares financial

"Each restricted stock unit ("RSU") represents the contingent right to receive one share of the Issuer's Ordinary Shares"

Ordinary shares are a type of ownership stake in a company, giving shareholders a right to participate in the company’s profits and decision-making through voting. They are similar to owning a piece of a business, and their value can rise or fall based on the company's performance. Investors buy ordinary shares to potentially earn dividends and benefit from the company's growth over time.

Disposition to issuer financial

"transaction_code_description": "Disposition to issuer""

vesting financial

"These RSUs reported in Table II are fully vested as of July 28, 2026"

Vesting is the process by which you earn full ownership of something, like company stock or a retirement benefit, over time. It’s like earning the right to keep a gift piece by piece the longer you stay with a company, making sure employees stay committed before they receive all the benefits.

FAQ

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

What insider transactions did Prothena (PRTA) report for Wagner M. Zago on July 28, 2026?

Prothena reported that Chief Scientific Officer Wagner M. Zago exercised 51,000 RSUs into ordinary shares on July 28, 2026 and, the same day, recorded a disposition to the issuer of 51,000 ordinary shares at $8.56 per share.

How many restricted stock units from the Prothena (PRTA) grant remain unvested for Wagner M. Zago?

From an original grant of 85,000 RSUs awarded on July 28, 2025, footnotes state that 34,000 RSUs remain subject to vesting. The 51,000 RSUs reported in this Form 4 were fully vested as of July 28, 2026.

What price was reported for Wagner M. Zago’s disposition of Prothena (PRTA) ordinary shares?

The Form 4 reports a transaction coded as a disposition to the issuer of 51,000 ordinary shares at a price of $8.56 per share. The filing does not characterize the purpose of this disposition beyond that code.

Were Prothena (PRTA) Chief Scientific Officer Wagner M. Zago’s transactions under a Rule 10b5-1 plan?

The Rule 10b5-1 checkbox in the Form 4 is not marked, and the footnotes do not mention any Rule 10b5-1 trading plan, indicating these transactions were not reported as being made under such a pre-arranged plan.

What does each Prothena (PRTA) RSU reported for Wagner M. Zago represent?

A footnote explains that each restricted stock unit (RSU) represents a contingent right to receive one ordinary share of Prothena upon vesting. Thus, 51,000 RSUs correspond to 51,000 ordinary shares when fully vested and settled.

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

Form 4 Insider Transactions: What Each Field Means →

See more from StockTitan in Google Search and AI answers. Adds StockTitan as a preferred source · opens Google

Add on Google Not now

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^*

Zago Wagner M.

(Last) (First) (Middle)

C/O PROTHENA BIOSCIENCES INC

1800 SIERRA POINT PARKWAY

(Street)

BRISBANE CALIFORNIA 94005

(City) (State) (Zip)

UNITED STATES

(Country)

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 Scientific Officer

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
07/28/2026

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

X	Form 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)
			Code	V	Amount	(A) or (D)	Price
Ordinary Shares, par value $0.01 per share	07/28/2026		M		51,000	A	(1)	85,000	D
Ordinary Shares, par value $0.01 per share	07/28/2026		D		51,000	D	$8.56	34,000	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(2)	(1)	07/28/2026		M			51,000	(3)	(3)	Ordinary Shares	51,000	$0	0	D

Explanation of Responses:

1. Each restricted stock unit ("RSU") represents the contingent right to receive one share of the Issuer's Ordinary Shares upon vesting.

2. These RSUs reported in Table II were granted to the Reporting Person on July 28, 2025 as part of an aggregate award of 85,000 RSUs and initially reported in Table I of the Form 4 filed on July 30, 2025, because they were solely settleable in shares at the time of grant. These RSUs are being moved to Table II as of this Form 4.

3. These RSUs reported in Table II are fully vested as of July 28, 2026 (the one-year anniversary of the grant date). The remainder of the 85,000 RSUs reported in Table I (34,000 RSUs) are subject to vesting.

	/s/ Michael J. Isaacs, as Attorney-in-Fact for Wagner M. Zago	07/30/2026
	** 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).
** 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)