Every Form 4 that Prothena Corporation plc (PRTA) has filed with the SEC in the last 12 months is listed below, newest first, and each one links through to the document itself with the summary and the scores our analysis gives it.
A Form 4 covers the transactions officers, directors and large holders report, so if you follow PRTA and want that one kind of document rather than the whole filing history, this is the page to keep. The company's other filings, of every form, are on the full PRTA filings page.
For PROTHENA CORP PUBLIC LTD CO (PRTA), ten percent owner William P. Scully purchased 100,000 ordinary shares on September 18, 2026 at a weighted average price of $8.4346 per share, with individual purchase prices ranging from $8.3350 to $8.4829. After this open-market purchase, he directly holds 927,000 shares, and also reports indirect holdings of 83,500 shares by Manatee Equity Fund LLC and 52,000 shares held by his spouse, with beneficial ownership of the Manatee Equity Fund LLC position disclaimed except to the extent of his pecuniary interest. No Rule 10b5-1 trading plan is reported for these transactions.
PROTHENA CORP PUBLIC LTD CO (PRTA) reporting person William P. Scully, a ten percent owner, purchased 27,000 ordinary shares on September 2, 2026 in open-market or private transactions at a weighted average price of $9.4718 per share, with individual prices ranging from $9.4072 to $9.6100.
After this purchase, he holds 827,000 shares directly, plus indirect holdings of 83,500 shares through Manatee Equity Fund LLC (for which he disclaims beneficial ownership except to the extent of his pecuniary interest) and 52,000 shares held by his spouse. No Rule 10b5-1 trading plan is reported.
PROTHENA CORP PUBLIC LTD CO (PRTA) reported that ten percent owner William P. Scully purchased 50,000 Ordinary Shares on August 20, 2026, in an open-market or private transaction at a weighted average price of $8.7886 per share. The price reflects multiple purchases at prices ranging from $8.7497 to $8.9000. Following this transaction, Scully directly holds 800,000 Ordinary Shares. He also is reported as having indirect ownership of 83,500 shares held by Manatee Equity Fund LLC, for which he disclaims beneficial ownership except to the extent of his pecuniary interest, and 52,000 shares held by his spouse.
PROTHENA CORP PUBLIC LTD CO (PRTA) reported insider activity by ten percent owner William P. Scully involving bona fide gifts of its ordinary shares. On August 18, 2026, he disposed of 627,553 ordinary shares as a bona fide gift at a reported price of $0.00 per share. On August 17, 2026, he was reported as acquiring 336,000 ordinary shares in a bona fide gift transaction. After these transactions, indirect holdings reported include 83,500 shares held by Manatee Equity Fund LLC, as to which he disclaims beneficial ownership except to the extent of his pecuniary interest, and 52,000 shares held by his spouse.
SCULLY WILLIAM P reported acquisition or exercise transactions in this Form 4 filing.
Prothena Corp Public Ltd Co reporting person William P. Scully, identified as a ten percent owner, reported receiving a bona fide gift of 251,553 Ordinary Shares of the company on 2026-08-10 at a stated price of $0.00 per share. Following this gift, he directly holds 1,041,553 Ordinary Shares. He also reports indirect holdings of 83,500 shares through Manatee Equity Fund LLC, for which he disclaims beneficial ownership beyond his pecuniary interest, and 52,000 shares held by his spouse.
Prothena Corp Public Ltd Co major shareholder William P. Scully reported open-market purchases of the company’s ordinary shares on August 7, 2026. He bought 34,000 shares directly and 3,500 shares through Manatee Equity Fund LLC at a weighted average price of $8.6192 per share, with trade prices ranging from $8.5094 to $8.7500. Following these trades, he reported 790,000 shares held directly and 83,500 shares held indirectly via Manatee Equity Fund LLC, while an additional 52,000 shares are reported as held indirectly by his spouse. The filer disclaims beneficial ownership of the Manatee-held shares except to the extent of his pecuniary interest.
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.
On July 28, 2026, Prothena Corp Public Ltd Co Chief Accounting Officer Karin L Walker exercised 15,000 restricted stock units into 15,000 ordinary shares, then disposed of 15,000 shares back to the issuer at $8.56 per share. These 15,000 RSUs, part of a 25,000-unit grant made on July 28, 2025, became fully vested on the one-year anniversary; the remaining 10,000 RSUs from that grant continue to be subject to vesting.
PROTHENA CORP PUBLIC LTD CO Chief Development Officer Chad J. Swanson exercised 51,000 restricted stock units into the same number of ordinary shares on July 28, 2026. On the same date he returned 40,800 shares to the issuer and had 3,467 shares withheld at $8.56 per share to pay the exercise price or tax liabilities. These RSUs were part of an 85,000‑unit grant made July 28, 2025, of which 34,000 RSUs remain subject to vesting.
PROTHENA CORP PUBLIC LTD CO reported that Chief Operating Officer Brandon S. Smith exercised 78,000 restricted stock units into the same number of ordinary shares on July 28, 2026, then disposed of 78,000 shares back to the issuer at $8.56 per share. These RSUs were part of a 130,000-unit grant from July 28, 2025, of which 52,000 RSUs remain subject to vesting.
PROTHENA CORP PUBLIC LTD CO officer Nguyen Tran, Chief Strategy Officer and CFO, exercised 57,000 restricted stock units into 57,000 ordinary shares on July 28, 2026, and on the same date disposed 57,000 ordinary shares to the issuer at $8.56 per share. These RSUs were part of a 95,000-unit award granted July 28, 2025; 38,000 RSUs from that grant remain subject to vesting.
PROTHENA CORP PUBLIC LTD CO President and CEO Gene G. Kinney exercised 84,000 restricted stock units into the same number of ordinary shares on July 28, 2026. These units were part of a 140,000 RSU grant awarded on July 28, 2025. On the same date, he disposed 84,000 ordinary shares back to the issuer at $8.56 per share. According to the award terms, the remaining 56,000 RSUs from that grant are still subject to future vesting.
Prothena Corp Public Ltd Co Chief Strategy Officer Anne Evans Kingston reported selling 7,662 ordinary shares on July 29, 2026 at a weighted average price of $8.4729, in multiple trades between $8.40 and $8.64, under a Rule 10b5-1 trading plan adopted on March 30, 2026. On July 28, 2026, 3,498 shares were disposed of at $8.56 per share to satisfy tax obligations by delivering or withholding securities.
PROTHENA CORP PUBLIC LTD CO General Counsel & Company Secretary Michael John Isaacs reported two transactions in ordinary shares. On July 29, 2026, he sold 8,386 shares in open-market or private trades at a weighted average of $8.4731 per share under a Rule 10b5-1 trading plan adopted on April 3, 2026. The trades were executed in multiple transactions at prices ranging from $8.40 to $8.65. On July 28, 2026, 4,694 shares were disposed of at $8.56 per share to satisfy exercise-price or tax-liability obligations by delivering or withholding shares. All transactions involved direct holdings.
PROTHENA CORP PUBLIC LTD CO large shareholder William P. Scully reported an open-market purchase of 20,000 ordinary shares of PRTA. The transaction occurred on June 16, 2026 at a weighted average price of $7.8995 per share, with individual trades between $7.8600 and $7.9312.
After this purchase, Scully directly holds 756,000 ordinary shares. The filing also shows indirect holdings of 52,000 shares held by his spouse and 80,000 shares held by Manatee Equity Fund LLC, for which he disclaims beneficial ownership except to the extent of his pecuniary interest.
PROTHENA CORP PUBLIC LTD CO ten percent owner William P. Scully reported a bona fide gift of 325,000 ordinary shares on June 15, 2026. The gift was recorded at a price of $0.00 per share.
After this transfer, Scully directly holds 736,000 ordinary shares and has additional indirect holdings of 52,000 shares through his spouse and 80,000 shares through Manatee Equity Fund LLC. He disclaims beneficial ownership of certain indirectly held securities except to the extent of his pecuniary interest.
Prothena Corp Public Ltd Co insider William P. Scully, a ten percent owner, bought 125,000 ordinary shares in an open-market purchase at a weighted average price of $8.1698 per share. The trade on June 11, 2026 increased his direct holdings to 1,061,000 ordinary shares.
The filing notes the shares were purchased in multiple transactions at prices ranging from $7.84 to $8.43 per share. It also reports additional indirect holdings of 52,000 shares held by his spouse and 80,000 shares held by Manatee Equity Fund LLC. Scully disclaims beneficial ownership of certain reported securities except to the extent of his pecuniary interest in them.
PROTHENA CORP PUBLIC LTD CO major shareholder William P. Scully reported an open-market purchase of 50,000 ordinary shares on June 4, 2026 at a weighted average price of $9.3059 per share. Following this transaction, he holds 936,000 shares directly.
He also reports indirect holdings of 52,000 shares by his spouse and 80,000 shares by Manatee Equity Fund LLC, and disclaims beneficial ownership of these indirect positions except to the extent of his pecuniary interest.
PROTHENA CORP PUBLIC LTD CO major shareholder William P. Scully reported an open-market purchase of 50,000 ordinary shares at a weighted average price of $9.426 per share on June 2, 2026. Following this transaction, he directly holds 886,000 ordinary shares.
The filing also lists indirect holdings of 52,000 shares held by his spouse and 80,000 shares held by Manatee Equity Fund LLC. The reporting person disclaims beneficial ownership of these securities except to the extent of his pecuniary interest in them.
PROTHENA CORP PUBLIC LTD CO major shareholder William P. Scully reported an open-market purchase of 100,000 ordinary shares of PRTA at a weighted average price of $9.813 per share. After this transaction, he directly held 836,000 ordinary shares.
The filing also lists indirect holdings of 52,000 shares held by his spouse and 80,000 shares held by Manatee Equity Fund LLC. A footnote states that he disclaims beneficial ownership of certain securities except to the extent of his pecuniary interest.
Prothena Corp Public Ltd Co director Daniel G. Welch received a grant of stock options on Ordinary Shares covering 27,000 shares at an exercise price of $9.76 per share. These options vest 100% on the earlier of the first anniversary of the May 15, 2026 grant date or the company’s 2027 annual general meeting, assuming he continues to serve as a director through that date. Following this grant, his reported derivative holdings in this option series total 27,000 shares, and the filing shows no related sales or exercises.
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.
Prothena Corp Public Ltd Co director Lars Ekman received a grant of stock options for 27,000 ordinary shares. The options have an exercise price of $9.76 per share and expire on May 15, 2036. They vest 100% on the earlier of the first anniversary of the grant date or the company’s 2027 annual general meeting, assuming he continues serving as a director until that vesting date. This is an equity compensation award rather than an open-market share purchase or sale.
PROTHENA CORP PUBLIC LTD CO director William H. Dunn Jr. received a grant of stock options covering 27,000 ordinary shares. The options have an exercise price of $9.76 per share, expire on May 15, 2036, and will vest 100% on the earlier of the first anniversary of the grant date or the company’s 2027 annual general meeting, assuming continuous board service.
PROTHENA CORP PUBLIC LTD CO director Shane Cooke received a grant of stock options covering 27,000 Ordinary Shares. The options carry an exercise price of $9.76 per share and expire on May 15, 2036. This is a compensation-related award, not an open-market purchase.
According to the terms, all 27,000 options will vest and become exercisable on the earlier of the first anniversary of the grant date or the day of the company’s 2027 annual general meeting, assuming he continues serving as a director until that vesting date.
PROTHENA CORP PUBLIC LTD CO director Richard T. Collier received a grant of stock options covering 27,000 ordinary shares. The options have an exercise price of $9.76 per share and expire on May 15, 2036. According to the award terms, all 27,000 options will vest and become exercisable on the earlier of the first anniversary of the May 15, 2026 grant date or the day of Prothena’s 2027 annual general meeting, provided he continues to serve as a director through that vesting date.
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.
Zago Wagner M. reported acquisition or exercise transactions in this Form 4 filing.
PROTHENA CORP PUBLIC LTD CO reported that Chief Scientific Officer Zago Wagner M. was granted a stock option covering 190,000 shares of the company’s stock. The option was reported at a grant price of $0.00 per share and is held as direct ownership.
According to the vesting terms, 25% of the total shares under the option will vest and become exercisable on March 3, 2027. The remaining shares will vest in 1/48th increments in equal monthly installments on each monthly anniversary after that date, conditioned on Wagner’s continued employment with the company on each vesting date.
PROTHENA CORP PUBLIC LTD CO reported that Chief Accounting Officer Karin L. Walker acquired a stock option covering 150,000 shares of the company’s stock. This option was reported as a grant or award acquisition in a Form 4 insider filing.
According to the vesting terms, 25% of the 150,000 shares subject to the option will vest and become exercisable on March 3, 2027. The remaining portion will vest in 1/48th increments in equal monthly installments on each monthly anniversary after that date, conditioned on Ms. Walker’s continued employment with the company on each vesting date.
PROTHENA CORP PUBLIC LTD CO reported that Chief Development Officer Chad J. Swanson acquired a grant of 190,000 stock options on March 3, 2026. The options were awarded at no cost as a “Stock Option (Right to Buy).”
According to the vesting terms, 25% of the total options will vest and become exercisable on March 3, 2027. The remaining options will vest in equal monthly installments of 1/48th of the total number of shares on each monthly anniversary thereafter, subject to his continued employment with the company on each vesting date.
PROTHENA CORP PUBLIC LTD CO granted Chief Operating Officer Brandon S. Smith a stock option covering 190,000 shares on March 3, 2026. This option was reported as a direct, derivative security and classified as a grant or award acquisition.
According to the vesting terms, 25% of the shares underlying the option will vest and become exercisable on March 3, 2027. The remaining shares will vest in 1/48th monthly installments on each monthly anniversary thereafter, conditioned on Smith’s continued employment with the company on each vesting date.
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.
Malecek Michael J reported acquisition or exercise transactions in this Form 4 filing.
Prothena Corp Public Ltd Co granted Chief Legal Officer Michael J. Malecek a stock option covering 190,000 shares of the company’s stock. According to the award terms, 25% of the option will vest and become exercisable on March 3, 2027. The remaining shares will vest in equal monthly installments of 1/48th of the total option on each monthly anniversary thereafter, subject to his continued employment with the company on each vesting date.
Kinney Gene G. reported acquisition or exercise transactions in this Form 4 filing.
PROTHENA CORP PUBLIC LTD CO reported that President and CEO Gene G. Kinney received a grant of stock options covering 520,000 shares on March 3, 2026. These options vest as to 25% of the total shares on March 3, 2027, then in equal monthly installments of 1/48th of the total shares on each monthly anniversary thereafter, subject to his continued employment with the company.