LYTIR

Company · PRTA

PROTHENA CORP PUBLIC LTD CO

In the 12 months to Nov 8, 2026: insiders bought on 14 occasions ($9.1M); insiders sold on 2 occasions ($136K); 3 filings by holders of 5% or more; 3 company reports (Form 8-K, since May 26, 2026).

All insider filings at the SEC

Insider purchases and sales, by month (last 12 months)Insider purchases: $9.1M in total; Insider sales: $136K in total.Jun: Insider purchases $158KJul: Insider sales $136KAug: Insider purchases $763KSep: Insider purchases $3.4MOct: Insider purchases $4.8MDecJanFebMarAprMayJunJulAugSepOctNov
Insider purchases above the line: $9.1MInsider sales below: $136K
Dollar value of open-market purchases and sales reported on SEC Form 4, by the month traded. Sales include pre-arranged 10b5-1 plan sales.

Insider trades · SEC Form 4

Those inside the hall

Open-market purchases and sales only. Legs one person filed for one day are combined.

Who traded

  1. SCULLY WILLIAM P bought on 14 days latest Oct 23, 2026 bought $9.1M
  2. Isaacs Michael John, General Counsel & Company Sec. sold on 1 day all under a 10b5-1 plan latest Jul 29, 2026 sold $71K
  3. Kingston Anne Evans, Chief Strategy Officer sold on 1 day all under a 10b5-1 plan latest Jul 29, 2026 sold $65K
Every trade (16)
  1. BUYSCULLY WILLIAM P bought Oct 23, 2026 50,000 shares filing $404K
  2. BUYSCULLY WILLIAM P bought Oct 22, 2026 100,000 shares filing $819K
  3. BUYSCULLY WILLIAM P bought Oct 14, 2026 10,000 shares filing $85K
  4. BUYSCULLY WILLIAM P bought Oct 13, 2026 100,000 shares filing $835K
  5. BUYSCULLY WILLIAM P bought Oct 8, 2026 90,000 shares filing $771K
  6. BUYSCULLY WILLIAM P bought Oct 7, 2026 125,000 shares filing $1.1M
  7. BUYSCULLY WILLIAM P bought Oct 2, 2026 100,000 shares filing $857K
  8. BUYSCULLY WILLIAM P bought Sep 29, 2026 162,000 shares filing $1.4M
  9. BUYSCULLY WILLIAM P bought Sep 28, 2026 103,500 shares filing $890K
  10. BUYSCULLY WILLIAM P bought Sep 18, 2026 100,000 shares filing $843K
  11. BUYSCULLY WILLIAM P bought Sep 2, 2026 27,000 shares filing $256K
  12. BUYSCULLY WILLIAM P bought Aug 20, 2026 50,000 shares filing $439K
  13. BUYSCULLY WILLIAM P bought Aug 7, 2026 37,500 shares 2 legs combined filing $323K
  14. SELLIsaacs Michael John, General Counsel & Company Sec. sold Jul 29, 2026 8,386 shares 10b5-1 plan (scheduled) filing $71K
  15. SELLKingston Anne Evans, Chief Strategy Officer sold Jul 29, 2026 7,662 shares 10b5-1 plan (scheduled) filing $65K
  16. BUYSCULLY WILLIAM P bought Jun 16, 2026 20,000 shares filing $158K

Large holders · SEC Schedules 13D and 13G

Five percent and over

Anyone who comes to hold more than 5% of a company's voting shares must tell the SEC. A Schedule 13D is filed by a holder who may seek to influence the company; a 13G by one who states it is a passive investor. An amendment updates an earlier filing, and a stake reported as 0% means the holder says it has sold all, or nearly all, of its shares. Every recent 13D and 13G

  1. Fennell Todd W. filed Aug 19, 2026 Schedule 13G/A passive filing 10.2%
  2. Fennell Todd W. filed Aug 14, 2026 Schedule 13G/A passive filing 9.8%
  3. FMR LLC filed Aug 6, 2026 Schedule 13G/A passive 7,199,218 shares filing 13.8%

Company reports · SEC Form 8-K

In its own words

Current reports the company filed with the SEC; most items are due within four business days of the event. Each line lists the report's items by the SEC's own titles; the filing says what happened. Reports collected since May 26, 2026; every 8-K at the SEC.

  1. Results of operations and financial condition filing Nov 5, 2026
  2. Termination of a material definitive agreement filing Oct 29, 2026
  3. Departure or appointment of directors or officers filing Oct 2, 2026

Sources: SEC EDGAR (Forms 4, 144 and 8-K) and STOCK Act periodic transaction reports. Filings can be late, amended or wrong at the source; see methodology.