Form 4: William P. Scully Reports Prothena Share Gift

Reporting person William P. Scully gifted 325,000 ordinary shares of Prothena Corp, reducing his direct holdings.

Summary

• William P. Scully, a 10% owner of Prothena Corp, executed a gift of 325,000 ordinary shares on June 15, 2026.
• The transaction was a bona fide gift with a price of $0 per share.
• Following the transaction, Mr. Scully's direct beneficial ownership stands at 736,000 shares.
• Mr. Scully maintains indirect ownership of 80,000 shares via Manatee Equity Fund LLC and 52,000 shares held by his spouse.

Sentiment

Score: 5

Explanation: StockSavvy.ai views this as a neutral event, as the transaction is a gift rather than a market sale, indicating no change in the insider's sentiment toward the company's future.

Positives

• The transaction represents a charitable or personal gift rather than a market-based divestment, which may signal long-term commitment to the remaining stake.

Negatives

• The reduction in direct beneficial ownership by 325,000 shares decreases the reporting person's direct voting power and equity stake in the company.

Risks

• Concentration risk remains as the reporting person continues to hold a significant stake in the company.

Future Outlook

No forward-looking guidance or strategic outlook was provided in this ownership disclosure.

Industry Context

StockSavvy.ai notes that insider gift filings are common among high-net-worth individuals for estate planning or philanthropic purposes and generally do not reflect a change in the insider's view of the company's fundamental prospects.

Comparison to Industry Standards

• The filing follows standard SEC disclosure requirements for 10% owners and insiders under Section 16(a).
• The use of a gift transaction is a standard mechanism for wealth transfer among major shareholders in the biotechnology sector.

Related Party Transactions

• The filing discloses indirect ownership through Manatee Equity Fund LLC and shares held by the reporting person's spouse.

Stakeholder Impact

• Minimal impact on shareholders as the shares remain within the reporting person's sphere of influence or are transferred to entities/individuals associated with the reporting person.

Next Steps

• No future actions or milestones were disclosed in this filing.

Key Dates

Keywords

Prothena, PRTA, Insider Trading, Form 4, Beneficial Ownership, William P. Scully