Prothena (NASDAQ: PRTA) awards 100,000 stock options to Chief Strategy Officer

Rhea-AI Filing Summary

PROTHENA CORP PUBLIC LTD CO granted Chief Strategy Officer Anne Evans Kingston a stock option covering 100,000 Ordinary Shares. The option has a grant exercise price of $10.50 per share and expires on April 10, 2036.

The award vests over four years: 25% of the shares vest and become exercisable on April 10, 2027, with the remaining shares vesting in equal monthly installments (1/48th of the total) on each monthly anniversary thereafter, contingent on her continued employment.

Insider Trade Summary

1 transaction reported

Mixed 1 txn

Insider Kingston Anne Evans

Role Chief Strategy Officer

Type	Security	Shares	Price	Value
Grant/Award	Stock Option (Right to Buy)	100,000	$0.00	--

Holdings After Transaction: Stock Option (Right to Buy) — 100,000 shares (Direct)

Footnotes (1)

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Key Figures

Options granted: 100,000 options Exercise price: $10.50 per share Expiration date: April 10, 2036 +3 more

6 metrics

Options granted 100,000 options Stock Option (Right to Buy) covering 100,000 Ordinary Shares

Exercise price $10.50 per share Conversion or exercise price of the granted stock option

Expiration date April 10, 2036 Option term end for the 100,000-share grant

Vesting cliff 25% on April 10, 2027 Initial vesting of the option grant

Ongoing vesting 1/48th monthly Equal monthly installments after initial 25% vesting

Post-grant derivative holdings 100,000 options Total derivative securities following transaction

Key Terms

Stock Option (Right to Buy), Ordinary Shares, exercise price, vesting, +1 more

5 terms

Stock Option (Right to Buy) financial

"security_title: "Stock Option (Right to Buy)""

Ordinary Shares financial

"underlying_security_title: "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.

exercise price financial

"conversion_or_exercise_price: "10.5000""

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.

vesting financial

"The shares subject to the option will vest and become exercisable as to 25%"

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.

expiration date financial

"expiration_date: "2036-04-10T00:00:00.000Z""

The expiration date is the deadline after which a financial contract, such as an option or a futures agreement, is no longer valid or can be exercised. It matters to investors because it determines the timeframe during which they can take action or benefit from the contract, similar to how a coupon or a food item has a limited period of usefulness. Once the expiration date passes, the contract loses its value or ability to be used.

Form 4 Insider Transactions: What Each Field Means →

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^*

Kingston Anne Evans

(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 Strategy Officer

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
04/10/2026

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

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)	$10.5	04/10/2026		A		100,000		(1)	04/10/2036	Ordinary Shares	100,000	$0	100,000	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 April 10, 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 J. Malecek, as Attorney-in-Fact for Anne E. Kingston	04/10/2026
	** 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)

FAQ

What did Prothena (PRTA) report in this Form 4 filing?

Prothena reported a grant of stock options to Chief Strategy Officer Anne Evans Kingston. She received options over 100,000 Ordinary Shares at an exercise price of $10.50 per share, with the options expiring on April 10, 2036 and vesting over four years.

Who is the insider in Prothena (PRTA)'s latest Form 4?

The insider is Anne Evans Kingston, Prothena’s Chief Strategy Officer. The filing shows a compensation-related grant of stock options, not an open-market purchase or sale, giving her the right to acquire up to 100,000 Ordinary Shares if the options vest and are exercised.

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

The new stock option covers 100,000 Ordinary Shares. These are derivative securities that give the Chief Strategy Officer the right to buy Prothena shares at a fixed exercise price of $10.50 per share, subject to the vesting schedule and continued employment conditions described.

What is the exercise price and term of the Prothena (PRTA) option grant?

The option has an exercise price of $10.50 per share and an expiration date of April 10, 2036. This means the holder may, once vested, choose to buy shares at $10.50 any time before that expiration, assuming all other conditions are met.

How does the Prothena (PRTA) stock option for the CSO vest over time?

The option vests in stages. 25% of the total 100,000 shares vest on April 10, 2027. The remaining 75% vest in equal monthly installments of 1/48th of the total on each monthly anniversary, conditioned on continued employment with Prothena.

Is the Prothena (PRTA) Form 4 transaction a market buy or sell of shares?

No, the transaction is a grant of stock options, coded as an acquisition (A) for compensation, not an open-market purchase or sale. It creates the right to buy shares in the future, subject to vesting, rather than an immediate trade in Ordinary Shares.