Tran B. Nguyen - 28 Jul 2026 Form 4 Insider Report for PROTHENA CORP PUBLIC LTD CO (PRTA)

Reporting relationship: Chief Strategy Officer and CFO
Issuer ticker: PRTA
Reported as of: 28 Jul 2026
Net transaction value: $0
SEC form: 4
Accepted by SEC: 30 Jul 2026, 20:32:28 UTC
Prior SEC filing: 05 Mar 2026
Source filing: View source filing
Reporting owner signature: /s/ Michael J. Isaacs, as Attorney-in-Fact for Tran B. Nguyen

Key filing fact

Tran B. Nguyen filed Form 4 for PROTHENA CORP PUBLIC LTD CO (PRTA) on 30 Jul 2026.

Key facts

This page summarizes Tran B. Nguyen's Form 4 filing for PROTHENA CORP PUBLIC LTD CO (PRTA).
3 reported transactions and 1 derivative row are listed below.
Accepted by SEC: 30 Jul 2026, 20:32.

Change

Previous filing in this sequence was filed on 05 Mar 2026.
Current net transaction value: $0.

Research use

This tells you what this filing adds before you inspect full transaction and derivative tables.
You can trace every row back to the original SEC filing document.

Evidence

Filed on Form 4

Ownership activity is grounded in SEC Form 4 disclosures.

View source filing

Reporting Owners (1)

CIK 0001457013 Primary reporting owner

Nguyen Tran

Relationship: Chief Strategy Officer and CFO
Address: C/O PROTHENA BIOSCIENCES INC, 1800 SIERRA POINT PARKWAY, BRISBANE
Signature: /s/ Michael J. Isaacs, as Attorney-in-Fact for Tran B. Nguyen
Signature date: 30 Jul 2026

Reported non-derivative transactions

Shares, units, or other non-derivative securities reported in this filing.

PRTA transaction

Ordinary Shares, par value $0.01 per share

Options Exercise

Transaction value
Shares: +57,000
Change %: +142%
Price
Shares after: 97,205
Date: 28 Jul 2026
Ownership: Direct
Footnotes: F1

PRTA transaction

Ordinary Shares, par value $0.01 per share

Disposed to Issuer

Transaction value
Shares: -57,000
Change %: -59%
Price: $8.56^*
Shares after: 40,205
Date: 28 Jul 2026
Ownership: Direct

Reported derivative securities

Options, warrants, convertible securities, or similar derivative positions disclosed in the filing.

PRTA transaction Derivative

Restricted Stock Units

Options Exercise

Transaction value
Shares: -57,000
Change %: -100%
Price: $0.000000^*
Shares after: 0
Date: 28 Jul 2026
Ownership: Direct
Underlying class: Ordinary Shares
Underlying amount: 57,000
Exercise price
Footnotes: F1, F2, F3

^* marks a reported price that did not pass the local price check.

Additional SEC filing notes

Filing notes and footnotes

Explanation of responses 3 footnotes

Footnote F1

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

Footnote F2

These RSUs reported in Table II were granted to the Reporting Person on July 28, 2025 as part of an aggregate award of 95,000 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.

Footnote 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 95,000 RSUs reported in Table I (38,000 RSUs) are subject to vesting.