Latest Period
Q1 2026
Security Snapshot
PROTHENA CORP PUBLIC LTD CO - Ordinary Shares, par value $0.01 per share (PRTA) Institutional Ownership
CUSIP: G72800108
13F Institutional Holders and Ownership History from Q1 2014 to Q1 2026
Institutions Reporting
184
Shares (Excl. Options)
46,980,757
Price
$9.72
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- Security type / class
- Equity / Ordinary Shares, par value $0.01 per share
- Symbol
- PRTA on Nasdaq
- All holders as of 31 Mar 2026
- Q1 2026
- Total 13F shares
- 46,980,757
- Total 13F value
- $456,614,522
- Portfolio coverage rank
- 0%
- Share change
- -321,270
- Value change
- -$2,870,675
- Number of holders
- 184
- Shares outstanding
- 53,821,313
- SEC-reported price per share
- $9.83
- Insider filing price
- $9.83
Latest holder snapshot
5 signals
Issuer context
Names, identifiers, and filing context for this profile.
3 identity fields
13F Shares, Excluding Options vs Price
13F Value, Excluding Options
Total Investors
Key facts
- PRTA - PROTHENA CORP PUBLIC LTD CO - Ordinary Shares, par value $0.01 per share is tracked under CUSIP G72800108.
- 184 institutions reported positions in Q1 2026.
- 7 significant owners is listed from Schedule 13D/13G reporting.
Change
- Holder count moved from 180 to 184 between Q4 2025 and Q1 2026.
- SEC-reported value moved from $451,174,680 to $456,614,522.
Research use
- You can quickly see who holds this security, then open quarter and manager detail pages for full evidence.
- 13F and Schedule 13D/13G sections are kept together so you can cross-check institutional and beneficial ownership context.
Evidence
Source: SEC Form 13F
Open SEC evidence
Latest holder context comes from 184 institutions filings for Q1 2026.
Security key
G72800108
Latest holder period
Q1 2026
13F holders
184
13D/G owners
7
CIK / CUSIP context first
Open Q1 2026 holders
PRTA full holder history
PROTHENA CORP PUBLIC LTD CO SEC filings
PROTHENA CORP PUBLIC LTD CO company facts
PROTHENA CORP PUBLIC LTD CO insider transactions
Broader feeds
Recent Quarterly Holder Reports
Open recent reporting periods for CUSIP G72800108:
13D/G owners
Significant owners
Large-stake holder rows connected to Schedule 13D/G evidence.
Rows
7
Security
PRTA
| Filer | Ownership | Change % | Holdings Value | Net Change | Nb Shares | Change % | Reporting Name | Report Period |
|---|---|---|---|---|---|---|---|---|
| SCULLY WILLIAM P | 10% | +5% | $53,949,825 | +$972,910 | 5,378,846 | +1.8% | SCULLY WILLIAM P | 07 May 2026 |
| Rubric Capital Management LP | 9.3% | +35% | $50,150,000 | +$13,266,370 | 5,000,000 | +36% | Rubric Capital Management LP | 31 Mar 2026 |
| Fennell Todd W. | 8.4% | +3.8% | $43,879,457 | +$1,415,200 | 4,495,846 | +3.3% | Fennell Todd W. | 30 Sep 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 Mar 2026, 184 institutional investors reported holding 46,980,757 shares of PROTHENA CORP PUBLIC LTD CO - Ordinary Shares, par value $0.01 per share (PRTA). This represents 87% of the company’s total 53,821,313 outstanding shares.
13F concentration
Top 25 institutional shareholders
Largest 13F positions for this security by reported shares and value.
Top holder share
72%
| Institution | Ownership % | Shares Held | Share Change % | Portfolio % | Holdings Value |
|---|---|---|---|---|---|
| FMR LLC | 14% | 7,551,218 | 0% | 0% | $73,397,839 |
| Rubric Capital Management LP | 9.3% | 5,000,000 | +36% | 0.6% | $48,600,000 |
| BlackRock, Inc. | 8.6% | 4,644,160 | +13% | 0% | $45,141,233 |
| STATE STREET CORP | 3.6% | 1,938,498 | -15% | 0% | $18,842,201 |
| D. E. Shaw & Co., Inc. | 3.3% | 1,763,347 | +4.9% | 0.01% | $17,139,733 |
| ADAR1 Capital Management, LLC | 2.9% | 1,581,443 | +8.5% | 0.93% | $15,371,626 |
| ACADIAN ASSET MANAGEMENT LLC | 2.9% | 1,547,593 | +7.7% | 0.02% | $15,037,000 |
| VANGUARD PORTFOLIO MANAGEMENT LLC | 2.7% | 1,445,979 | 0% | 0% | $14,054,916 |
| MORGAN STANLEY | 2.3% | 1,230,448 | -1.3% | 0% | $11,959,961 |
| Palo Alto Investors LP | 2.2% | 1,208,568 | -8.5% | 1.8% | $11,747,281 |
| TWO SIGMA INVESTMENTS, LP | 2.2% | 1,205,978 | +80% | 0.01% | $11,722,106 |
| GEODE CAPITAL MANAGEMENT, LLC | 2% | 1,098,166 | +3.3% | 0% | $10,676,629 |
| FEDERATED HERMES, INC. | 2% | 1,059,849 | +8.8% | 0.02% | $10,301,732 |
| JACOBS LEVY EQUITY MANAGEMENT, INC | 1.8% | 972,017 | -0.61% | 0.04% | $9,448,005 |
| GOLDMAN SACHS GROUP INC | 1.5% | 818,885 | -12% | 0% | $7,959,563 |
| DIMENSIONAL FUND ADVISORS LP | 1.5% | 782,603 | +0.95% | 0% | $7,606,336 |
| Nuveen, LLC | 1.4% | 759,368 | +0.03% | 0% | $7,381,057 |
| Qube Research & Technologies Ltd | 1.1% | 614,603 | +51% | 0.01% | $5,973,941 |
| RENAISSANCE TECHNOLOGIES LLC | 1.1% | 607,515 | +39% | 0.01% | $5,905,046 |
| Mariner, LLC | 1% | 563,082 | -2.6% | 0.01% | $5,473,134 |
| MONIMUS CAPITAL MANAGEMENT, LP | 0.9% | 485,617 | +91% | 1.3% | $4,720,197 |
| VANGUARD CAPITAL MANAGEMENT LLC | 0.9% | 484,126 | 0% | 0% | $4,705,705 |
| Rangeley Capital, LLC | 0.84% | 449,460 | -14% | 4.7% | $4,368,751 |
| Birchview Capital, LP | 0.83% | 449,019 | +1.8% | 2.5% | $4,364,465 |
| ARMISTICE CAPITAL, LLC | 0.82% | 439,411 | -71% | 0.14% | $4,271,075 |
Quarter history
Institutional holders across reporting periods
Holder count, reported shares/value, and median price by quarter.
Periods
49
Latest
Q1 2026
Rows shown
1-25 of 49
| Period | 13F Shares, Excl. Options | Value, Excl. Options | Value Change | Price (Median) | Investors |
|---|---|---|---|---|---|
| 2026 Q1 | 46,980,757 | $456,614,522 | -$2,870,675 | $9.72 | 184 |
| 2025 Q4 | 47,239,418 | $451,174,680 | +$43,863,231 | $9.55 | 180 |
| 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 |