United States Biotechnology & Medical Research

Prothena Corporation PLC (PRTA)

Track

Over the past 90 days, Prothena Corporation PLC saw 8 insider transactions, resulting in a net positive value of approximately $3.1 million. Activity was driven by significant buying from William P. Scully, while other officers engaged in proposed sales. This follows a recent earnings report where the company exceeded EPS expectations by 326.67%.
Ticker: PRTA Exchange: NSM
Preparing chart...
Download chart Copy chart image Copy link Share to X Share


• Purchase • Sale • Planned purchase • Planned sale Net purchase Net sale Buy signal Sell signal Earnings
Upgrade for signal details

Upgrade to see score, net flow, insiders and context.

Upgrade to see full signal details →

Insider trades have triggered activity signals for Prothena Corporation PLC. Upgrade to see score, net flow, insiders and the full signal context.

Open in Activity Signals screener →
Top insiders
Trades
Planned sale 29 Jul 2026
Value US$3,211,429.52 | Price 140.18 | Shares 99,272 (-2.8%)
Abbreviations B: Buy, S: Sell, PP: Planned purchase, PlS: Planned sale, PrS: Proposed sale, O: Option / Other
Notification date Transaction date B/S Transaction type Insider and/or position Nb. shares
Price
Value 		Number of shares Price Value Details
2026-07-30 2026-07-29 PlS Planned sale
Kingston Anne Evans

Chief Strategy Officer

Officer
99,272 -2.8%
140.18
US$3,211,430 		99,272 -2.8% 140.18 US$3,211,430
2026-07-30 2026-07-29 PlS Planned sale
Isaacs Michael John

General Counsel & Company Sec.

Officer
51,721 -47.0%
71.41
US$3,053,599 		51,721 -47.0% 71.41 US$3,053,599
2026-07-29 2026-07-29 PrS Proposed sale
ANNE KINGSTON

Officer

Officer
67,148
327.11
US$2,915,098 		67,148 327.11 US$2,915,098
2026-07-29 2026-07-29 PrS Proposed sale
MICHAEL JOHN ISAACS

Officer

Officer
1,000
8.47
US$100,000 		1,000 8.47 US$100,000
2026-06-18 2026-06-16 B Purchase
1.8
SCULLY WILLIAM P
Large shareholder
20,000 +2.7%
7.90
US$157,990 		20,000 +2.7% 7.90 US$157,990
2026-06-12 2026-06-11 B Purchase
1.8
SCULLY WILLIAM P
Large shareholder
125,000 +13.4%
8.17
US$1,021,225 		125,000 +13.4% 8.17 US$1,021,225
2026-06-09 2026-06-09 PrS Proposed sale
MALECEK MICHAEL J

Previous Officer

Officer
80,000
9.25
US$740,000 		80,000 9.25 US$740,000
2026-06-05 2026-06-04 B Purchase
1.8
SCULLY WILLIAM P
Large shareholder
50,000 +5.6%
9.31
US$465,295 		50,000 +5.6% 9.31 US$465,295
2026-06-03 2026-06-02 B Purchase
1.8
SCULLY WILLIAM P
Large shareholder
50,000 +6.0%
9.43
US$471,300 		50,000 +6.0% 9.43 US$471,300
2026-05-26 2026-05-22 B Purchase
1.8
SCULLY WILLIAM P
Large shareholder
100,000 +13.6%
9.81
US$981,300 		100,000 +13.6% 9.81 US$981,300
2025-05-06 2025-05-06 S Sale
3.1
EcoR1 Capital, LLC
Large shareholder
1,984,053 -27.2%
7.64
US$15,164,712 		1,984,053 -27.2% 7.64 US$15,164,712
2025-05-06 2025-05-05 S Sale
3.1
EcoR1 Capital, LLC
Large shareholder
977,693 -11.8%
8.11
US$7,930,166 		977,693 -11.8% 8.11 US$7,930,166
2025-05-06 2025-05-02 S Sale
3.1
EcoR1 Capital, LLC
Large shareholder
3,317,938 -28.6%
8.36
US$27,744,929 		3,317,938 -28.6% 8.36 US$27,744,929
2025-05-02 2025-01-14 B Purchase
1.8
SCULLY WILLIAM P
Large shareholder
100,000 +15.7%
12.79
US$1,279,040 		100,000 +15.7% 12.79 US$1,279,040
2025-05-02 2024-12-31 B Purchase
1.8
SCULLY WILLIAM P
Large shareholder
30,000 +4.8%
12.99
US$389,640 		30,000 +4.8% 12.99 US$389,640
2025-05-02 2024-12-31 B Purchase
1.8
SCULLY WILLIAM P
Large shareholder
800 +0.1%
13.39
US$10,715 		800 +0.1% 13.39 US$10,715
2025-05-02 2024-12-31 B Purchase
1.8
SCULLY WILLIAM P
Large shareholder
1,200 +0.2%
13.37
US$16,038 		1,200 +0.2% 13.37 US$16,038
2025-05-02 2024-12-20 B Purchase
1.8
SCULLY WILLIAM P
Large shareholder
2,000 +0.3%
15.91
US$31,813 		2,000 +0.3% 15.91 US$31,813
2025-05-02 2024-12-18 B Purchase
1.8
SCULLY WILLIAM P
Large shareholder
73,436 +6.0%
13.93
US$1,022,670 		73,436 +6.0% 13.93 US$1,022,670
2024-01-24 2024-01-24 PrS Proposed sale
Walker Karin L

Officer

Officer
5,000
34.00
US$170,000 		5,000 34.00 US$170,000
2024-01-24 2024-01-24 PlS Planned sale
Walker Karin L

Chief Accounting Officer

Officer
5,000 -100.0%
34.00
US$170,000 		5,000 -100.0% 34.00 US$170,000
2023-12-20 2023-12-20 PrS Proposed sale
Walker Karin L

Officer

Officer
5,000
37.29
US$186,450 		5,000 37.29 US$186,450
2023-12-20 2023-12-20 PlS Planned sale
Walker Karin L

Chief Accounting Officer

Officer
3,322 -100.0%
37.45
US$124,409 		3,322 -100.0% 37.45 US$124,409
2023-12-20 2023-12-20 PlS Planned sale
Walker Karin L

Chief Accounting Officer

Officer
1,678 -33.6%
36.68
US$61,543 		1,678 -33.6% 36.68 US$61,543
2023-11-30 2023-11-30 PrS Proposed sale
Walker Karin L

Officer

Officer
5,000
34.00
US$170,000 		5,000 34.00 US$170,000
2023-11-30 2023-11-30 PlS Planned sale
Walker Karin L

Chief Accounting Officer

Officer
5,000 -100.0%
34.00
US$170,000 		5,000 -100.0% 34.00 US$170,000
2023-10-25 2023-10-25 PrS Proposed sale
Walker Karin L

Officer

Officer
5,000
41.27
US$206,350 		5,000 41.27 US$206,350
2023-10-25 2023-10-25 PlS Planned sale
Walker Karin L

Chief Accounting Officer

Officer
294 -100.0%
42.28
US$12,430 		294 -100.0% 42.28 US$12,430
2023-10-25 2023-10-25 PlS Planned sale
Walker Karin L

Chief Accounting Officer

Officer
2,917 -90.8%
41.38
US$120,718 		2,917 -90.8% 41.38 US$120,718
2023-10-25 2023-10-25 PlS Planned sale
Walker Karin L

Chief Accounting Officer

Officer
1,789 -35.8%
40.27
US$72,043 		1,789 -35.8% 40.27 US$72,043
2023-10-11 2023-10-11 PrS Proposed sale
Smith Brandon S.

Officer

Officer
4,000
47.29
US$189,160 		4,000 47.29 US$189,160
2023-10-11 2023-10-11 PlS Planned sale
Smith Brandon S.

Chief Operating Officer

Officer
444 -100.0%
47.74
US$21,198 		444 -100.0% 47.74 US$21,198
2023-10-11 2023-10-11 PlS Planned sale
Smith Brandon S.

Chief Operating Officer

Officer
3,556 -88.9%
46.62
US$165,786 		3,556 -88.9% 46.62 US$165,786
2023-10-04 2023-10-04 PrS Proposed sale
Karp Carol D.

Officer

Officer
5,000
47.40
US$237,000 		5,000 47.40 US$237,000
2023-10-04 2023-10-04 PlS Planned sale
Karp Carol D.

Chief Regulatory Officer

Officer
663 -100.0%
47.29
US$31,355 		663 -100.0% 47.29 US$31,355
2023-10-04 2023-10-04 PlS Planned sale
Karp Carol D.

Chief Regulatory Officer

Officer
4,337 -86.7%
46.51
US$201,729 		4,337 -86.7% 46.51 US$201,729
2023-09-27 2023-09-27 PrS Proposed sale
Malecek Michael J

Officer

Officer
5,000
48.21
US$241,050 		5,000 48.21 US$241,050
2023-09-27 2023-09-27 PlS Planned sale
Malecek Michael J

Chief Legal Officer

Officer
404 -100.0%
48.31
US$19,519 		404 -100.0% 48.31 US$19,519
2023-09-27 2023-09-27 PlS Planned sale
Malecek Michael J

Chief Legal Officer

Officer
4,596 -91.9%
47.29
US$217,366 		4,596 -91.9% 47.29 US$217,366
2023-09-25 2023-09-25 PrS Proposed sale
2.5
Patel Sanjiv

Director

Non-Executive Director
35,000
50.00
US$1,750,000 		35,000 50.00 US$1,750,000
2023-09-19 2023-09-19 PrS Proposed sale
KARIN WALKER

Officer

Officer
5,000
52.36
US$261,806 		5,000 52.36 US$261,806
2023-09-19 2023-09-19 PlS Planned sale
Walker Karin L

Chief Accounting Officer

Officer
5,000 -100.0%
52.36
US$261,807 		5,000 -100.0% 52.36 US$261,807
2023-09-13 2023-09-13 PrS Proposed sale
Garren Hideki

Officer

Officer
2,000
55.39
US$110,780 		2,000 55.39 US$110,780
2023-09-13 2023-09-13 PrS Proposed sale
Smith Brandon S.

Officer

Officer
4,000
55.39
US$221,560 		4,000 55.39 US$221,560
2023-09-13 2023-09-13 PlS Planned sale
Smith Brandon S.

Chief Operating Officer

Officer
114 -100.0%
55.96
US$6,379 		114 -100.0% 55.96 US$6,379
2023-09-13 2023-09-13 PlS Planned sale
Smith Brandon S.

Chief Operating Officer

Officer
3,886 -97.2%
55.48
US$215,584 		3,886 -97.2% 55.48 US$215,584
2023-09-13 2023-09-13 PlS Planned sale
Garren Hideki

Chief Medical Officer

Officer
2,000 -100.0%
55.48
US$110,952 		2,000 -100.0% 55.48 US$110,952
2023-09-06 2023-09-06 PrS Proposed sale
Karp Carol D.

Officer

Officer
5,000
54.61
US$273,050 		5,000 54.61 US$273,050
2023-09-06 2023-09-06 PlS Planned sale
Karp Carol D.

Chief Regulatory Officer

Officer
6 -100.0%
55.27
US$332 		6 -100.0% 55.27 US$332
2023-09-06 2023-09-06 PlS Planned sale
Karp Carol D.

Chief Regulatory Officer

Officer
4,994 -99.9%
54.76
US$273,472 		4,994 -99.9% 54.76 US$273,472
2023-08-30 2023-08-30 PrS Proposed sale
Malecek Michael J

Officer

Officer
5,000
55.01
US$275,066 		5,000 55.01 US$275,066
2023-08-30 2023-08-30 PlS Planned sale
Malecek Michael J

Chief Legal Officer

Officer
14 -100.0%
56.21
US$787 		14 -100.0% 56.21 US$787
2023-08-30 2023-08-30 PlS Planned sale
Malecek Michael J

Chief Legal Officer

Officer
2,664 -99.5%
55.39
US$147,551 		2,664 -99.5% 55.39 US$147,551
2023-08-30 2023-08-30 PlS Planned sale
Malecek Michael J

Chief Legal Officer

Officer
2,322 -46.4%
54.58
US$126,728 		2,322 -46.4% 54.58 US$126,728
2023-08-18 2023-08-18 PrS Proposed sale
KARIN WALKER

Officer

Officer
5,000
57.18
US$285,922 		5,000 57.18 US$285,922
2023-08-18 2023-08-18 PlS Planned sale
Walker Karin L

Chief Accounting Officer

Officer
5,000 -100.0%
57.18
US$285,922 		5,000 -100.0% 57.18 US$285,922
2023-08-16 2023-08-16 PrS Proposed sale
Smith Brandon S.

Officer

Officer
4,000
58.71
US$234,844 		4,000 58.71 US$234,844
2023-08-16 2023-08-16 PrS Proposed sale
Garren Hideki

Officer

Officer
2,000
58.74
US$117,480 		2,000 58.74 US$117,480
2023-08-16 2023-08-16 PlS Planned sale
Smith Brandon S.

Chief Operating Officer

Officer
401 -100.0%
59.91
US$24,025 		401 -100.0% 59.91 US$24,025
2023-08-16 2023-08-16 PlS Planned sale
Smith Brandon S.

Chief Operating Officer

Officer
1,373 -77.4%
59.15
US$81,217 		1,373 -77.4% 59.15 US$81,217
2023-08-16 2023-08-16 PlS Planned sale
Smith Brandon S.

Chief Operating Officer

Officer
2,226 -55.6%
58.22
US$129,602 		2,226 -55.6% 58.22 US$129,602
2023-08-16 2023-08-16 PlS Planned sale
Garren Hideki

Chief Medical Officer

Officer
374 -100.0%
59.74
US$22,341 		374 -100.0% 59.74 US$22,341
2023-08-16 2023-08-16 PlS Planned sale
Garren Hideki

Chief Medical Officer

Officer
748 -66.7%
58.93
US$44,079 		748 -66.7% 58.93 US$44,079
2023-08-16 2023-08-16 PlS Planned sale
Garren Hideki

Chief Medical Officer

Officer
878 -43.9%
58.15
US$51,059 		878 -43.9% 58.15 US$51,059
2023-08-02 2023-08-02 PrS Proposed sale
Zago Wagner M.

Officer

Officer
4,000
67.05
US$268,182 		4,000 67.05 US$268,182
2023-08-02 2023-08-02 PrS Proposed sale
Karp Carol D.

Officer

Officer
5,000
67.01
US$335,072 		5,000 67.01 US$335,072
2023-08-02 2023-08-02 PlS Planned sale
Karp Carol D.

Chief Regulatory Officer

Officer
328 -100.0%
67.95
US$22,288 		328 -100.0% 67.95 US$22,288
2023-08-02 2023-08-02 PlS Planned sale
Karp Carol D.

Chief Regulatory Officer

Officer
4,672 -93.4%
66.95
US$312,784 		4,672 -93.4% 66.95 US$312,784
2023-08-02 2023-08-02 PlS Planned sale
Zago Wagner M.

Chief Scientific Officer

Officer
229 -100.0%
68.07
US$15,589 		229 -100.0% 68.07 US$15,589
2023-08-02 2023-08-02 PlS Planned sale
Zago Wagner M.

Chief Scientific Officer

Officer
3,771 -94.3%
66.98
US$252,593 		3,771 -94.3% 66.98 US$252,593
2023-07-26 2023-07-26 PrS Proposed sale
Malecek Michael J

Officer

Officer
5,000
62.33
US$311,638 		5,000 62.33 US$311,638
2023-07-26 2023-07-26 PlS Planned sale
Malecek Michael J

Chief Legal Officer

Officer
620 -100.0%
63.40
US$39,309 		620 -100.0% 63.40 US$39,309
2023-07-26 2023-07-26 PlS Planned sale
Malecek Michael J

Chief Legal Officer

Officer
1,903 -75.4%
62.69
US$119,297 		1,903 -75.4% 62.69 US$119,297
2023-07-26 2023-07-26 PlS Planned sale
Malecek Michael J

Chief Legal Officer

Officer
2,477 -49.5%
61.78
US$153,032 		2,477 -49.5% 61.78 US$153,032
2023-07-19 2023-07-19 PrS Proposed sale
KARIN WALKER

Officer

Officer
5,000
69.19
US$345,943 		5,000 69.19 US$345,943
Explore more

More insider trading research around Prothena Corporation PLC

More insider trades in United States
Similar Healthcare companies with insider activity
More Pharmaceuticals & Medical Research companies with insider activity
More Biotechnology & Medical Research companies with insider activity
Insider trading in North America