Prothena Corporation plc (PRTA) has 20 known insider and institutional holders on record. The largest holder is NODELMAN OLEG with 9,426,640 shares. Other notable holders include EcoR1 Capital, LLC and SCULLY WILLIAM P.
Over the last 12 months, insiders have made 34 transactions in PRTA stock — 25 buys (valued at $17.94M) and 3 sells (valued at $50.84M). Insider buying has outpaced selling during this period, which may signal confidence in the company's prospects.
PRTA Insider Ownership
Top Holder
NODELMAN OLEG
9,426,640 shares
Buys (12 mo)
25
$17.94M value
Sells (12 mo)
3
$50.84M value
12-Month Transaction Activity
Top Insider Holders
| # |
Name |
Role |
Shares Owned |
Last Filed |
Relative Size |
| 1 |
Nodelman Oleg |
10 Percent Owner |
9,426,640 |
2019-12-13 |
|
| 2 |
Ecor1 Capital, Llc |
10 Percent Owner |
8,266,342 |
2025-05-06 |
|
| 3 |
Scully William P |
10 Percent Owner |
1,224,257 |
2025-05-02 |
|
| 4 |
Kinney Gene G. |
President and CEO |
520,000 |
2026-03-05 |
|
| 5 |
Nguyen Tran |
Chief Strategy Officer and CFO |
230,000 |
2026-03-05 |
|
| 6 |
Schenk Dale B. |
President and CEO |
200,000 |
2016-02-26 |
|
| 7 |
Swanson Chad J. |
Chief Development Officer |
190,000 |
2026-03-05 |
|
| 8 |
Malecek Michael J |
Chief Legal Officer |
190,000 |
2026-03-05 |
|
| 9 |
Smith Brandon S. |
Chief Operating Officer |
190,000 |
2026-03-05 |
|
| 10 |
Zago Wagner M. |
Chief Scientific Officer |
190,000 |
2026-03-05 |
|
| 11 |
Homan Arthur W |
Chief Legal Officer |
150,000 |
2018-06-25 |
|
| 12 |
Walker Karin L |
Chief Accounting Officer |
150,000 |
2026-03-05 |
|
| 13 |
Karp Carol D. |
Chief Regulatory Officer |
107,500 |
2025-03-07 |
|
| 14 |
Ford David A |
Chief People Officer |
107,500 |
2025-03-07 |
|
| 15 |
Mcninch David B. |
Chief Commercial Officer |
100,000 |
2016-02-26 |
|
| 16 |
Noonberg Sarah B. |
Chief Medical Officer |
100,000 |
2017-05-18 |
|
| 17 |
Garren Hideki |
Chief Medical Officer |
85,000 |
2024-02-29 |
|
| 18 |
Tripuraneni Radhika |
Chief Development Officer |
50,000 |
2022-02-25 |
|
| 19 |
Koller Martin |
Chief Medical Officer |
50,000 |
2016-02-26 |
|
| 20 |
Nickerson Tara |
Chief Business Officer |
45,000 |
2018-02-23 |
|
Recent Transactions (last 12 months)
| Date |
Name |
Role |
Type |
Shares |
Price |
Value |
| 2026-03-03 |
Swanson Chad J. |
Chief Development Officer |
RSU Award |
190,000 |
$9.36 |
$1.78M |
| 2026-03-03 |
Smith Brandon S. |
Chief Operating Officer |
RSU Award |
190,000 |
$9.36 |
$1.78M |
| 2026-03-03 |
Malecek Michael J |
Chief Legal Officer |
RSU Award |
190,000 |
$9.36 |
$1.78M |
| 2026-03-03 |
Zago Wagner M. |
Chief Scientific Officer |
RSU Award |
190,000 |
$9.36 |
$1.78M |
| 2026-03-03 |
Kinney Gene G. |
President and CEO |
RSU Award |
520,000 |
$9.36 |
$4.87M |
| 2026-03-03 |
Walker Karin L |
Chief Accounting Officer |
RSU Award |
150,000 |
$9.36 |
$1.4M |
| 2026-03-03 |
Nguyen Tran |
Chief Strategy Officer and CFO |
RSU Award |
230,000 |
$9.36 |
$2.15M |
| 2025-07-28 |
Swanson Chad J. |
Chief Development Officer |
RSU Award |
85,000 |
- |
- |
| 2025-07-28 |
Smith Brandon S. |
Chief Operating Officer |
RSU Award |
130,000 |
- |
- |
| 2025-07-28 |
Malecek Michael J |
Chief Legal Officer |
RSU Award |
80,000 |
- |
- |
| 2025-07-28 |
Zago Wagner M. |
Chief Scientific Officer |
RSU Award |
85,000 |
- |
- |
| 2025-07-28 |
Kinney Gene G. |
President and CEO |
RSU Award |
140,000 |
- |
- |
| 2025-07-28 |
Walker Karin L |
Chief Accounting Officer |
RSU Award |
25,000 |
- |
- |
| 2025-07-28 |
Nguyen Tran |
Chief Strategy Officer and CFO |
RSU Award |
95,000 |
- |
- |
| 2025-05-14 |
Dunn William H. Jr. |
Director |
RSU Award |
20,183 |
$6.89 |
$138.96K |
| 2025-05-14 |
Cobb Paula K |
Director |
RSU Award |
20,183 |
$6.89 |
$138.96K |
| 2025-05-14 |
Selkoe Dennis J. |
Director |
RSU Award |
20,183 |
$6.89 |
$138.96K |
| 2025-05-14 |
Cooke Shane |
Director |
RSU Award |
20,183 |
$6.89 |
$138.96K |
| 2025-05-14 |
Kim Helen Susan |
Director |
RSU Award |
20,183 |
$6.89 |
$138.96K |
| 2025-05-14 |
Ekman Lars |
Director |
RSU Award |
20,183 |
$6.89 |
$138.96K |
| 2025-05-14 |
Welch Daniel G |
Director |
RSU Award |
20,183 |
$6.89 |
$138.96K |
| 2025-05-14 |
Collier Richard T |
Director |
RSU Award |
20,183 |
$6.89 |
$138.96K |
| 2025-05-06 |
Ecor1 Capital, Llc |
10 Percent Owner |
Informative Sell |
1,984,053 |
$7.64 |
$15.16M |
| 2025-05-05 |
Ecor1 Capital, Llc |
10 Percent Owner |
Informative Sell |
977,693 |
$8.11 |
$7.93M |
| 2025-05-02 |
Ecor1 Capital, Llc |
10 Percent Owner |
Informative Sell |
3,317,938 |
$8.36 |
$27.74M |
