PROTHENA CORP PUBLIC LTD CO - Ordinary Shares, par value $0.01 per share (PRTA) Institutional Ownership

13F Institutional Holders and Ownership History from Q1 2014 to Q4 2025

Type / Class
Equity / Ordinary Shares, par value $0.01 per share
Symbol
PRTA on Nasdaq
Shares outstanding
53,840,864
Price per share
$8.98
All holders as of 31 Dec 2025
Q4 2025
Total 13F shares
47,212,058
Total reported value
$450,917,552
% of total 13F portfolios
0%
Share change
+4,630,134
Value change
+$43,961,144
Number of holders
177
Price from insider filings
$8.98
Reported Shares, Excluding Options vs Price
Reported Value, Excluding Options
Total Investors

Significant Owners of PROTHENA CORP PUBLIC LTD CO - Ordinary Shares, par value $0.01 per share (PRTA) based on Schedule 13D/G filings

Filer Ownership Change % Holdings Value Net Change Nb Shares Change % Reporting Name Report Period
SCULLY WILLIAM P 9.8% -1% $51,550,817 -$683,200 5,281,846 -1.3% SCULLY WILLIAM P 30 Sep 2025
Fennell Todd W. 8.4% +3.8% $43,879,457 +$1,415,200 4,495,846 +3.3% Fennell Todd W. 30 Sep 2025
Rubric Capital Management LP 6.8% $33,022,432 3,677,331 Rubric Capital Management LP 31 Dec 2025
BlackRock, Inc. 5.7% $30,180,467 3,092,261 BlackRock, Inc. 30 Sep 2025
ADAR1 Capital Management, LLC 2.7% -60% $14,338,396 -$18,601,691 1,469,098 -56% ADAR1 Capital Management, LLC 30 Sep 2025
WELLINGTON MANAGEMENT GROUP LLP 0.2% -93% $821,299 -$38,122,050 108,208 -98% Wellington Management Group LLP 30 May 2025
PRICE T ROWE ASSOCIATES INC /MD/ 0.1% $449,017 71,047 T. Rowe Price Associates, Inc. 30 Jun 2025

As of 31 Dec 2025, 177 institutional investors reported holding 47,212,058 shares of PROTHENA CORP PUBLIC LTD CO - Ordinary Shares, par value $0.01 per share (PRTA). This represents 88% of the company’s total 53,840,864 outstanding shares.

Top 25 Institutional Shareholders

The largest institutional shareholders of PROTHENA CORP PUBLIC LTD CO - Ordinary Shares, par value $0.01 per share (PRTA) together control 72% of the company’s outstanding shares — a level of ownership often associated with strong institutional conviction and long‑term capital commitment.

Institution Ownership % Shares Held Share Change % Portfolio % Holdings Value
FMR LLC 14% 7,551,218 -4.4% 0% $72,114,132
BlackRock, Inc. 7.6% 4,107,459 +14% 0% $39,226,235
Rubric Capital Management LP 6.8% 3,677,331 +139% 0.42% $35,118,511
STATE STREET CORP 4.2% 2,267,802 +152% 0% $21,657,509
VANGUARD GROUP INC 4% 2,140,909 +4.4% 0% $20,445,681
D. E. Shaw & Co., Inc. 3.1% 1,681,369 +28% 0.01% $16,057,074
ARMISTICE CAPITAL, LLC 2.8% 1,500,000 -18% 0.35% $14,325,000
ADAR1 Capital Management, LLC 2.7% 1,457,764 -0.77% 1% $13,921,646
ACADIAN ASSET MANAGEMENT LLC 2.7% 1,437,358 +16% 0.02% $13,720,000
Palo Alto Investors LP 2.5% 1,320,510 -0.27% 1.8% $12,610,871
MORGAN STANLEY 2.3% 1,246,774 +56% 0% $11,906,695
GEODE CAPITAL MANAGEMENT, LLC 2% 1,063,069 +4.3% 0% $10,154,236
JACOBS LEVY EQUITY MANAGEMENT, INC 1.8% 978,011 +12% 0.04% $9,340,005
FEDERATED HERMES, INC. 1.8% 974,367 +41% 0.02% $9,305,205
GOLDMAN SACHS GROUP INC 1.7% 935,333 +165% 0% $8,932,430
CITADEL ADVISORS LLC 1.7% 912,382 +19% 0.01% $8,713,248
Point72 Asset Management, L.P. 1.6% 860,018 +33% 0.01% $8,213,172
DIMENSIONAL FUND ADVISORS LP 1.4% 775,207 -3.9% 0% $7,402,857
Nuveen, LLC 1.4% 759,107 +14% 0% $7,249,472
TWO SIGMA INVESTMENTS, LP 1.2% 670,138 +57% 0.01% $6,399,818
Mariner, LLC 1.1% 577,938 -2.2% 0.01% $5,519,157
Rangeley Capital, LLC 0.97% 524,600 -6.4% 4.4% $5,009,930
Birchview Capital, LP 0.82% 441,019 -20% 2.5% $4,211,731
RENAISSANCE TECHNOLOGIES LLC 0.81% 435,515 +17% 0.01% $4,159,168
JANE STREET GROUP, LLC 0.8% 428,651 -31% 0% $4,093,617

Institutional Holders of PROTHENA CORP PUBLIC LTD CO - Ordinary Shares, par value $0.01 per share (PRTA) across Reporting Periods

Period Reported Shares, Excl. Options Value, Excl. Options Value Change Price (Median) Investors
2025 Q4 47,212,058 $450,917,552 +$43,961,144 $9.55 177
2025 Q3 42,604,772 $415,804,752 +$14,066,211 $9.76 186
2025 Q2 41,776,362 $253,618,091 -$154,368,994 $6.07 189
2025 Q1 52,255,320 $646,537,943 -$15,376,892 $12.38 159
2024 Q4 53,520,384 $741,301,350 +$19,669,947 $13.85 169
2024 Q3 50,853,296 $851,220,146 -$23,732,004 $16.73 161
2024 Q2 50,815,366 $1,048,817,908 -$59,472,211 $20.64 158
2024 Q1 53,460,655 $1,324,229,375 -$21,764,361 $24.77 167
2023 Q4 53,582,486 $1,947,737,140 -$9,488,527 $36.34 185
2023 Q3 52,971,709 $2,555,148,423 +$29,971,909 $48.25 183
2023 Q2 51,720,763 $3,531,607,158 +$12,834,911 $68.28 193
2023 Q1 51,855,543 $2,513,406,409 +$112,382,536 $48.47 190
2022 Q4 49,429,867 $2,978,072,979 +$298,095,364 $60.25 200
2022 Q3 44,446,558 $2,694,628,592 -$49,390,014 $60.63 172
2022 Q2 44,544,535 $1,209,363,430 +$9,495,997 $27.15 148
2022 Q1 44,090,735 $1,613,250,005 +$36,002,082 $36.57 157
2021 Q4 42,838,679 $2,116,102,912 +$71,220,544 $49.40 178
2021 Q3 40,926,820 $2,915,195,629 +$43,595,404 $71.23 178
2021 Q2 40,413,096 $2,077,425,322 +$59,094,190 $51.41 145
2021 Q1 39,992,237 $1,004,673,605 +$172,031,286 $25.12 136
2020 Q4 34,820,788 $418,200,137 -$14,386,569 $12.01 125
2020 Q3 36,213,293 $361,767,623 -$14,703,289 $9.99 122
2020 Q2 37,685,325 $394,185,304 +$5,496,127 $10.46 122
2020 Q1 37,171,691 $397,733,636 +$362,298 $10.70 111
2019 Q4 36,900,713 $584,063,976 -$14,804,972 $15.83 118
2019 Q3 37,519,336 $294,147,092 -$35,540,498 $7.84 104
2019 Q2 38,707,372 $408,977,541 -$3,322,709 $10.57 115
2019 Q1 39,552,356 $479,768,599 -$5,204,022 $12.13 113
2018 Q4 40,191,353 $413,964,989 -$11,042,997 $10.30 94
2018 Q3 40,703,212 $532,428,709 -$19,192,710 $13.08 106
2018 Q2 41,819,930 $609,738,338 -$64,279,542 $14.58 99
2018 Q1 42,230,566 $1,550,277,237 -$42,502,431 $36.71 125
2017 Q4 43,319,402 $1,624,043,307 -$24,135,490 $37.49 136
2017 Q3 43,097,542 $2,791,538,622 +$48,547,383 $64.77 137
2017 Q2 42,520,819 $2,301,219,492 +$50,542,051 $54.12 131
2017 Q1 41,586,908 $2,319,785,592 +$352,776,129 $55.79 134
2016 Q4 37,883,135 $1,863,485,839 +$78,335,772 $49.19 129
2016 Q3 36,188,824 $2,168,791,786 +$91,518,874 $59.97 124
2016 Q2 34,721,856 $1,214,078,050 -$16,834,885 $34.96 121
2016 Q1 34,953,403 $1,438,709,150 +$168,112,705 $41.16 124
2015 Q4 30,076,055 $2,048,538,890 -$250,555 $68.11 144
2015 Q3 30,096,238 $1,364,556,716 +$27,932,560 $45.34 131
2015 Q2 29,462,340 $1,551,776,990 +$216,495,938 $52.67 122
2015 Q1 25,370,071 $967,610,808 +$43,080,212 $38.14 108
2014 Q4 24,776,976 $516,560,605 -$1,495,459 $20.76 107
2014 Q3 21,497,219 $476,372,873 -$17,119,907 $22.16 108
2014 Q2 22,266,639 $502,097,582 -$53,582,899 $22.55 113
2014 Q1 20,861,255 $799,170,611 +$188,798,037 $38.31 104