Director William P. Scully filed a Form 4 with the SEC on August 10, 2026, disclosing the purchase of 37,500 ordinary shares of Prothena Corp Public Ltd Co (NASDAQ: PRTA) on August 7, 2026.

Key Highlights

  • Direct purchase: Scully acquired 34,000 ordinary shares directly at a weighted average price of $8.6192 per share on August 7, 2026.
  • Indirect purchase: An additional 3,500 shares were acquired indirectly through Manatee Equity Fund LLC at the same weighted average price of $8.6192 per share.
  • Price range: According to the filing, shares were purchased in multiple transactions at prices ranging from $8.5094 to $8.7500, inclusive.
  • Post-transaction direct holdings: Following the reported transactions, Scully directly beneficially owns 790,000 ordinary shares.
  • Indirect holdings: Scully indirectly holds 83,500 shares through Manatee Equity Fund LLC and 52,000 shares held by his spouse.
  • Disclaimer: The filing states Scully "disclaims beneficial ownership of these securities except to the extent of his pecuniary interest therein" regarding the Manatee Equity Fund LLC shares.

Scully's August 2026 Open-Market Purchases of Prothena Ordinary Shares

According to the filing, William P. Scully, identified as a director of Prothena Corp Public Ltd Co, reported two purchase transactions in ordinary shares, par value $0.01 per share, both dated August 7, 2026. The transactions were coded "P," indicating open-market purchases. The form was signed by Reid E. Buchanan by power of attorney from William P. Scully and filed on August 10, 2026.

The filing disclosed that the 34,000 directly acquired shares and the 3,500 indirectly acquired shares were each transacted at a weighted average price of $8.6192 per share. The filing notes that these shares were purchased across multiple transactions at prices ranging from $8.5094 to $8.7500, inclusive, and that full information regarding the number of shares purchased at each separate price is available upon request to the company, any security holder, or the SEC staff.

Following the reported transactions, Scully's direct beneficial ownership stands at 790,000 ordinary shares. Indirectly, he holds 83,500 shares through Manatee Equity Fund LLC and 52,000 shares through his spouse. No derivative securities transactions were reported in Table II of this filing.

What Was Disclosed

The filing reported the purchase of 37,500 total ordinary shares of Prothena Corp Public Ltd Co by director William P. Scully on August 7, 2026, at a weighted average price of $8.6192, with 34,000 shares held directly and 3,500 held through Manatee Equity Fund LLC.