PRTA · Insider trading · 13F holders · Congress trades
Prothena Corp Public LTD Co (PRTA)
Who is buying and selling PRTA: company insiders on SEC Form 4, hedge funds and superinvestors on Form 13F, and members of Congress under the STOCK Act. Every figure links to the filing or page it comes from.
- 13F filers holding
- 7
- Insider buys, 90 days
- $9.0M
- Insider sales, 90 days
- $0
- Congress trades, 12 months
- 0
PRTA at a glance
- Between Aug 1, 2026 and Oct 29, 2026, 1 PRTA insider filed 10 open-market purchases worth $9.0M on SEC Form 4.
- 7 13F filers hold PRTA among their 50 largest positions, worth $41.9M combined. The biggest bets by portfolio weight are Rangeley Capital, LLC (3.8%), Birchview Capital, LP (2.1%) and Palo Alto Investors LP (1.5%).
- No member of Congress has disclosed a trade in PRTA.
- PRTA last closed at $8.88 on Oct 29, 2026.
PRTA insider trading
Between Aug 1, 2026 and Oct 29, 2026, 1 PRTA insider filed 10 open-market purchases worth $9.0M on SEC Form 4.
| Filed | Insider | Role | Trade | Shares | Price | Value | Form 4 |
|---|---|---|---|---|---|---|---|
| Oct 26, 2026 | Scully William P | 10% Owner | Buy | 150,000 | $8.15 | $1.2M | SEC |
| Oct 15, 2026 | Scully William P | 10% Owner | Buy | 110,000 | $8.36 | $920K | SEC |
| Oct 9, 2026 | Scully William P | 10% Owner | Buy | 215,000 | $8.47 | $1.8M | SEC |
| Oct 6, 2026 | Scully William P | 10% Owner | Buy | 100,000 | $8.57 | $857K | SEC |
| Sep 30, 2026 | Scully William P | 10% Owner | Buy | 162,000 | $8.68 | $1.4M | SEC |
| Sep 29, 2026 | Scully William P | 10% Owner | Buy | 103,500 | $8.60 | $890K | SEC |
| Sep 21, 2026 | Scully William P | 10% Owner | Buy | 100,000 | $8.43 | $843K | SEC |
| Sep 3, 2026 | Scully William P | 10% Owner | Buy | 27,000 | $9.47 | $256K | SEC |
| Aug 21, 2026 | Scully William P | 10% Owner | Buy | 50,000 | $8.79 | $439K | SEC |
| Aug 10, 2026 | Scully William P | 10% Owner | Buy | 37,500 | $8.62 | $323K | SEC |
Who owns PRTA? Hedge funds and superinvestors
7 13F filers hold PRTA among their 50 largest positions, worth $41.9M combined. The biggest bets by portfolio weight are Rangeley Capital, LLC (3.8%), Birchview Capital, LP (2.1%) and Palo Alto Investors LP (1.5%).
| Manager | % of portfolio | Value | Shares | Last quarter | 13F |
|---|---|---|---|---|---|
| ADAR1 Capital Management, LLCHedge fund | 0.7% | $15.2M | 1,554,535 | -1.7% shares | Q2 2026 |
| Palo Alto Investors LPHedge fund | 1.5% | $11.2M | 1,143,155 | -5.4% shares | Q2 2026 |
| Birchview Capital, LPWealth manager | 2.1% | $4.4M | 449,019 | +0.0% shares | Q2 2026 |
| Rangeley Capital, LLCHedge fund | 3.8% | $4.1M | 417,270 | -7.2% shares | Q2 2026 |
| Monimus Capital Management, LPHedge fund | 0.8% | $3.2M | 329,052 | -32.2% shares | Q2 2026 |
| Penbrook Management LLCWealth manager | 1.3% | $2.3M | 271,720 | +0.0% shares | Q3 2026 |
| Diadema Partners LPHedge fund | 0.6% | $1.5M | 149,482 | — | Q2 2026 |
Each manager counts with its latest 13F (Q3 2026: 1, Q2 2026: 6). Screen PRTA in the grand portfolio →
PRTA stock trades by members of Congress
No member of Congress has disclosed a trade in PRTA.
Analysis mentioning PRTA
Posts from the blog that cover Prothena Corp Public LTD Co, newest first.
- Insider buying · Oct 26, 2026Insider Buying on October 26, 2026: GPI, CRBG and BPRE Lead $42.0M of Purchases
- Insider buying · Oct 15, 2026Insider Buying on October 15, 2026: CRBG, BORR and FLSC Lead $23.8M of Purchases
- Insider buying · Oct 9, 2026Insider Buying on October 9, 2026: GGR, CRBG and BPRE Lead $70.3M of Purchases
- Insider buying · Oct 6, 2026Insider Buying on October 6, 2026: PSUS, AVR and CRBG Lead $87.1M of Purchases
- Insider buying · Sep 30, 2026Insider Buying on September 30, 2026: KOD, GPI and LEN Lead $422.1M of Purchases
- Insider buying · Sep 29, 2026Insider Buying on September 29, 2026: ADRX, COUR and GME Lead $86.7M of Purchases
- Insider buying · Sep 21, 2026Insider Buying on September 21, 2026: LEN, GRAB and GSAT Lead $352.7M of Purchases
PRTA questions and answers
Are insiders buying PRTA stock?
Between Aug 1, 2026 and Oct 29, 2026, 1 PRTA insider filed 10 open-market purchases worth $9.0M on SEC Form 4.
Which hedge funds own PRTA?
7 13F filers hold PRTA among their 50 largest positions, worth $41.9M combined. The biggest bets by portfolio weight are Rangeley Capital, LLC (3.8%), Birchview Capital, LP (2.1%) and Palo Alto Investors LP (1.5%).
Has Congress traded PRTA?
No member of Congress has disclosed a trade in PRTA.
Who is the largest holder of PRTA?
Among 13F filers, ADAR1 Capital Management, LLC reports the largest PRTA position, $15.2M (1,554,535 shares) in its Q2 2026 13F. The biggest bet by portfolio weight is Rangeley Capital, LLC's: 3.8% of its portfolio.
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