$PRTA

Prothena (PRTA), Rapport (RAPP), and Azenta (AZTA) are on a watchlist due to insider buying and share repurchases. PRTA's 10% owner bought 27,000 shares at $9.47, with $272.2M cash and no debt. RAPP insiders bought $1.66M in shares, with $815.4M in cash post-financing. AZTA repurchased 2.3M shares, with $529M in cash. All await catalysts: PRTA's Alzheimer's trial data, RAPP's epilepsy study, and AZTA's fiscal 2027 outlook.

SCULLY WILLIAM P purchased 140,000 shares of PROTHENA CORP PUBLIC LTD CO (PRTA) at $8.53 ($1.19M total) on 2026-11-09.

Prothena (PRTA) reported Q3 EPS of -$0.32, missing estimates by $0.11, with revenue of $620K, below the $9.59M consensus. The stock is down 9.93% over 3 months and 25.28% over 12 months. InvestingPro rates its financial health as 'good performance'.

Prothena Corp. (PRTA) reported a Q3 loss of $16.5M, or 32 cents per share, beating analyst expectations of a 38 cents per share loss. The company generated $620K in revenue. According to Zacks Investment Research, the average estimate was for a larger loss.

Prothena reported Q3 2026 net loss of $16.5M and 9M net loss of $2.4M, with $272.2M in cash. Coramitug showed reduced hsCRP in Phase 2 trial. Roche and Novo highlight prasinezumab and coramitug for Parkinson's and ATTR-CM. Phase 3 trials expected to complete in 2029. Prothena has $650M in upfront payments and potential $2.25B in milestones. Preclinical programs include TDP-43 CYTOPE and PRX012-TfR.

PROTHENA CORP PUBLIC LTD CO (PRTA) filed an SEC Form 8-K — Results of Operations and Financial Condition. Exhibit 99.1 PRESS RELEASE Prothena Reports Third Quarter 2026 Financial Results an d Business Highlights • Net cash used in operating and investing activities was $12.0 million in the third quarter and net cash used in operating and investing activities was $8.9 million for the

PROTHENA CORP PUBLIC LTD CO (PRTA) filed an SEC Form 8-K — Termination of a Material Definitive Agreement. Item 1.02 Termination of a Material Definitive Agreement. Following an internal strategic review, Bristol Myers Squibb informed Prothena Corporation plc (the “ Company ”) on October 28, 2026 that it has decided not to advance PRX019 further in the clinic. In May 2024, a subsidiar

William P. Scully, a 10% owner of Prothena, bought 150,000 shares in two transactions, totaling $1.22M. The average prices were $8.1852 and $8.0705 per share. Scully now directly owns 1.19M shares and indirectly owns 716,000 shares, according to an SEC filing.

SCULLY WILLIAM P purchased 150,000 shares of PROTHENA CORP PUBLIC LTD CO (PRTA) at an average of $8.15 ($8.07–$8.19, $1.22M total) across 2 trades over 2026-10-22 to 2026-10-23.

SCULLY WILLIAM P purchased 110,000 shares of PROTHENA CORP PUBLIC LTD CO (PRTA) at an average of $8.36 ($8.35–$8.46, $0.92M total) across 2 trades over 2026-10-13 to 2026-10-14.