William Scully Increases Stake in Prothena Corporation

William Scully, an insider at Prothena Corporation plc, purchased 20,000 shares of the company on June 16, 2026. He bought the shares at an average price of $7.90 each, making the transaction worth $158,000. This move adds to Scully's growing position in the biotechnology firm.

Other Institutional Activity in Prothena

Several institutional investors have also made moves in Prothena. FMR LLC maintained its position with 7,551,218 shares valued at approximately $73.4 million. Rubric Capital Management LP increased its stake by 1,322,669 shares, bringing its total to 5 million shares worth about $48.6 million. BlackRock, Inc. added 536,701 shares, resulting in a total holding of 4,644,160 shares valued at $45.1 million. Meanwhile, State Street Corp decreased its position by 329,304 shares, leaving it with 1,938,498 shares worth $18.8 million.

Prothena Corporation plc Stock Down 5.7%

Shares of NasdaqGS:PRTA are currently trading near $8.80. Prothena Corporation has a market cap of approximately $444.5 million. The stock's 52-week low is $5.64, and its high is $11.80. The 50-day moving average is $9.92, while the 200-day moving average is $9.63. Prothena's current ratio stands at 10.43, with a quick ratio of 10.13 and a debt-to-equity ratio of 2.45.

Recent Earnings

Prothena reported revenue of $57.94 million, reflecting a growth of 17.1% over the previous period. However, the company posted a negative net margin of 260.9% and a return on equity of -40.3%. The next earnings report is expected on August 3, 2026.

Insider Buying and Selling at Prothena Corporation plc

William Scully has been active in trading Prothena shares recently. On June 16, 2026, he bought 20,000 shares at $7.90 each. Earlier in June, he made several purchases, including 125,000 shares at $8.17 on June 11 and 50,000 shares at $9.31 on June 4. Scully also sold 325,000 shares on June 15, 2026.

Analysts Set New Price Targets

On May 8, 2026, Citizens maintained its 'buy' rating for Prothena with a price target of $20. RBC Capital has kept a 'hold' rating with a $12 target since February 20, 2026. The consensus among analysts is a 'buy' rating, with a mean target price of $21.40 based on five opinions.

About Prothena Corporation

Prothena Corporation plc is a biotechnology company based in Dublin, Ireland. It focuses on developing therapies for diseases caused by protein misfolding. The company has a range of products in various stages of clinical trials, including treatments for Parkinson's disease and Alzheimer's disease. It collaborates with major pharmaceutical companies like Roche and Bristol Myers Squibb.

Bottom Line

William Scully's recent purchase of Prothena shares highlights ongoing insider interest in the company. While Prothena's stock has shown volatility, its pipeline of therapies holds potential for future growth. Investors often watch insider transactions as part of their analysis, but it's essential to remember that such filings reflect past actions and may not indicate current positions.