Prothena (PRTA) director receives stock option grant for 27,000 shares

Filing Impact

(Neutral)

Filing Sentiment

(Neutral)

Form Type

Rhea-AI Filing Summary

PROTHENA CORP PUBLIC LTD CO director Dennis J. Selkoe received a grant of stock options for 27,000 shares. These options give the right to buy ordinary shares at an exercise price of $9.76 per share and are held as a direct ownership position.

The options will vest and become exercisable in full on the earlier of the first anniversary of the May 15, 2026 grant date or the day of the company’s 2027 annual general meeting, assuming he continues serving as a director through that date. After this grant, he holds options covering 27,000 shares.

Insider Trade Summary

1 transaction reported

Mixed 1 txn

Insider Selkoe Dennis J.

Role null

Type	Security	Shares	Price	Value
Grant/Award	Stock Option (Right to Buy)	27,000	$0.00	--

Holdings After Transaction: Stock Option (Right to Buy) — 27,000 shares (Direct, null)

Footnotes (1)

[object Object]

Key Figures

Option grant size: 27,000 shares Exercise price: $9.76 per share Post-grant option holdings: 27,000 shares +1 more

4 metrics

Option grant size 27,000 shares Stock options granted to director on May 15, 2026

Exercise price $9.76 per share Exercise price for the stock option grant

Post-grant option holdings 27,000 shares Total options held following the reported transaction

Option expiration May 15, 2036 Expiration date of the stock options

Key Terms

Stock Option (Right to Buy), exercise price, derivative securities, vesting

4 terms

Stock Option (Right to Buy) financial

"security_title: Stock Option (Right to Buy)"

exercise price financial

"conversion_or_exercise_price: 9.7600"

The exercise price is the fixed amount at which you can buy or sell an asset, like a stock, when using an options contract. It matters because it helps determine whether exercising the option will be profitable or not, depending on the current market price. Think of it as the set price you agree on today to buy or sell later.

derivative securities financial

"derivativeTransactionCount: 1 (derivative-type records)"

Financial contracts whose value is tied to the price or performance of another asset, such as a stock, bond, commodity, index, or currency; examples include options, futures and swaps. They matter to investors because they let you protect against price swings, bet on future moves or gain larger exposure with less upfront cash—like using a lever or insurance policy on an investment—so they can amplify gains and losses and help manage portfolio risk.

vesting financial

"The shares subject to the option will vest and become exercisable"

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.

Form 4 Insider Transactions: What Each Field Means →

05/15/2026 - 09:28 PM

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^*

Selkoe Dennis J.

(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)

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

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
05/15/2026

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)
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	Code	V	Amount	(A) or (D)	Price		6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)

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)
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)	Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	8. Price of Derivative Security (Instr. 5)		10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
Stock Option (Right to Buy)	$9.76	05/15/2026		A		27,000		⁽¹⁾	05/15/2036	Ordinary Shares	27,000	$0	27,000	D

Explanation of Responses:

1. The shares subject to the option will vest and become exercisable as to 100% of the total number of shares subject to the option on the earlier of the first anniversary of the grant date or the day of the annual general meeting in 2027 of the Issuer's shareholders, assuming continuous service as a director until such vesting date.

	/s/ Michael J. Malecek, as Attorney-in-Fact for Dennis J. Selkoe	05/15/2026
	** 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)

Source: View Original Filing on SEC EDGAR

FAQ

What did Prothena (PRTA) director Dennis J. Selkoe report on this Form 4?

Dennis J. Selkoe reported receiving a grant of stock options covering 27,000 ordinary shares of Prothena. The grant is a compensation-related award, giving him the right to buy shares at a fixed $9.76 exercise price in the future once the options vest.

How many Prothena (PRTA) shares are covered by the new stock option grant?

The stock option grant covers 27,000 ordinary shares of Prothena. These options represent the right to purchase that number of shares once they vest and become exercisable, subject to the specified vesting conditions tied to time and board service.

What is the exercise price of Dennis Selkoe’s Prothena (PRTA) stock options?

The options have an exercise price of $9.76 per share. This means Selkoe can buy Prothena ordinary shares at $9.76 once the options vest and are exercised, regardless of the market price at that future time.

When do Dennis Selkoe’s Prothena (PRTA) stock options vest?

The options vest 100% on the earlier of the first anniversary of the May 15, 2026 grant date or the day of Prothena’s 2027 annual general meeting. Vesting requires his continuous service as a director through the applicable vesting date.

Is Dennis Selkoe’s Prothena (PRTA) option grant a buy or sell transaction?

The Form 4 reflects an acquisition of derivative securities through a grant, not a market purchase or sale. It is coded as a grant or award of stock options, which is a typical director compensation arrangement rather than an open-market trading decision.

How many Prothena (PRTA) options does Dennis Selkoe hold after this grant?

Following the reported transaction, Selkoe holds stock options covering 27,000 ordinary shares. This total reflects the newly granted options as his reported derivative holdings in this filing, all held as a direct ownership position.