PROTHENA CORP PLC PRTA
SHS · Common Stock · CUSIP G72800108
- SectorHealth care
- IndustryPharmaceutical Preparations
- FilingsSEC EDGAR
* Summed across managers. Shares that two managers' reports both contain – a subsidiary's holdings that its parent's report includes too, or a sub-adviser's in its client's – are counted once ($154.0k this quarter). Holder counts are more reliable. Shares outstanding: 53.8m as of 2024-08-01, from the company's own SEC filing; the percentage can still exceed 100%: lent-out shares are counted by the lender and the buyer, and some reports overlap without saying so. Implied quarter-end price ≈ $20.64. Options: 7 managers hold calls ($2.0m notional), 8 hold puts ($2.3m).
Trends to Q2 2024
Institutional holders
Managers reporting a position, each quarter
Numbers
| Quarter | Holders |
|---|---|
| Q3 2022 | 183 |
| Q4 2022 | 201 |
| Q1 2023 | 192 |
| Q2 2023 | 197 |
| Q3 2023 | 188 |
| Q4 2023 | 188 |
| Q1 2024 | 170 |
| Q2 2024 | 161 |
Buyers vs sellers
Managers adding to or starting a position, vs cutting or selling out
Numbers
| Quarter | Bought or added | Cut or sold out |
|---|---|---|
| Q4 2022 | 116 | 74 |
| Q1 2023 | 97 | 87 |
| Q2 2023 | 99 | 86 |
| Q3 2023 | 98 | 83 |
| Q4 2023 | 99 | 84 |
| Q1 2024 | 81 | 102 |
| Q2 2024 | 82 | 77 |
Calls vs puts
Options held, notional value, last 4 quarters. P/C = puts ÷ calls
Numbers
| Quarter | Calls | Puts | P/C |
|---|---|---|---|
| Q3 2023 | $9.6m | $18.1m | 1.88 |
| Q4 2023 | $81.9m | $62.6m | 0.76 |
| Q1 2024 | $4.8m | $4.8m | 1.00 |
| Q2 2024 | $2.0m | $2.3m | 1.14 |
Biggest buyers
| ARMISTICE CAPITAL, LLC | Added | +464.0k |
| BlackRock Inc. | Added | +138.3k |
| AXA S.A. | Added | +120.8k |
| CITADEL ADVISORS LLC | Added | +118.2k |
| Prosight Management, LP | Added | +116.5k |
| PDT Partners, LLC | New | +102.7k |
| TWO SIGMA INVESTMENTS, LP | New | +71.6k |
| GEODE CAPITAL MANAGEMENT, LLC | Added | +69.7k |
| Birchview Capital, LP | Added | +68.0k |
| JANE STREET GROUP, LLC | Added | +67.1k |
Biggest sellers
| STATE STREET CORP | Reduced | -1.5m |
| MORGAN STANLEY | Reduced | -1.1m |
| First Light Asset Management, LLC | Sold out | -445.0k |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC | Reduced | -332.1k |
| MILLENNIUM MANAGEMENT LLC | Reduced | -290.9k |
| JANUS HENDERSON GROUP PLC | Reduced | -283.0k |
| CITIGROUP INC | Reduced | -235.2k |
| Rafferty Asset Management, LLC | Reduced | -206.4k |
| Qube Research & Technologies Ltd | Sold out | -195.4k |
| UBS Group AG | Reduced | -153.9k |
Biggest calls
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Reduced | $1.1m55.2k shares |
| CITADEL ADVISORS LLC | Reduced | $344.7k16.7k shares |
| SIMPLEX TRADING, LLC | Unchanged | $245.0k11.9k shares |
| JANE STREET GROUP, LLC | Reduced | $227.0k11.0k shares |
| GROUP ONE TRADING LLC | Reduced | $61.9k3.0k shares |
| Walleye Capital LLC | Reduced | $16.5k800 shares |
| CONCOURSE FINANCIAL GROUP SECURITIES, INC. | Unchanged | $00 shares |
Biggest puts
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Reduced | $654.3k31.7k shares |
| CITADEL ADVISORS LLC | Added | $555.2k26.9k shares |
| GROUP ONE TRADING LLC | Reduced | $272.4k13.2k shares |
| GTS SECURITIES LLC | Added | $241.5k11.7k shares |
| D. E. Shaw & Co., Inc. | New | $229.1k11.1k shares |
| SIMPLEX TRADING, LLC | Reduced | $187.0k9.1k shares |
| Walleye Capital LLC | Added | $171.3k8.3k shares |
| CONCOURSE FINANCIAL GROUP SECURITIES, INC. | Unchanged | $00 shares |
Options at notional value: the value of the shares the contracts control, as filers report them, not what the options cost. Not included in the holders, shares or buying above.
Major shareholders (over 5%)
Anyone who owns more than 5% of a class of the company's shares has to say so: on Schedule 13D if they may try to influence or control the company, on 13G if they're a passive investor, and update it as the stake changes. Each holder's latest filing, from 19 Dec 2024 on; percentages are of the share class, as the holder worked them out.
| Holder | Stake |
|---|---|
| FMR LLC 13G · institution filed 2026-08-06 | 13.8% |
| SCULLY WILLIAM P 13G · passive investor +0.5 pts · filed 2026-05-11 | 10.3% |
| Fennell Todd W. 13G · passive investor +0.4 pts · filed 2026-08-19 | 10.2% |
| Rubric Capital Management LP 13G · institution +2.5 pts · filed 2026-05-15 | 9.3% |
| BlackRock, Inc. 13G · institution +1.2 pts · filed 2026-07-29 | 6.9% |
Fell to 5% or below in the last year: ADAR1 Capital Management, LLC (2.7%, 2025-11-14)
Insider purchases and sales in Q2 2024
Shares bought or sold by the company's own officers, directors and 10% owners, in the open market or privately, as they reported to the SEC on Form 4 (due within two business days of the trade). Grants, option exercises, shares withheld for tax and gifts aren't included.
Officers and directors buying vs selling
Number of people, by quarter (10% owners not included)
Numbers
| Quarter | Buying | Bought | Selling | Sold | Sold under a plan |
|---|---|---|---|---|---|
| Q3 2022 | 0 | — | 6 | $10.6m | — |
| Q4 2022 | 0 | — | 7 | $14.4m | — |
| Q1 2023 | 0 | — | 7 | $5.7m | $245.1k |
| Q2 2023 | 0 | — | 9 | $17.2m | $17.2m |
| Q3 2023 | 0 | — | 7 | $4.6m | $4.6m |
| Q4 2023 | 0 | — | 3 | $981.2k | $981.2k |
| Q1 2024 | 0 | — | 1 | $170.0k | $170.0k |
| Q2 2024 | 0 | — | 0 | — | — |
None reported in Q2 2024.
Holders, Q2 2024
| Manager | Shares | Change |
|---|---|---|
| EcoR1 Capital, LLC 7.31% of their portfolio | 11.6m $239.1m | Unchanged |
| FMR LLC 0.01% of their portfolio | 8.1m $166.5m | Added +59.3k |
| PRICE T ROWE ASSOCIATES INC /MD/ 0.01% of their portfolio | 4.2m $87.5m | Added +35.6k |
| BlackRock Inc. 0.00% of their portfolio | 3.9m $79.6m | Added +138.3k |
| WELLINGTON MANAGEMENT GROUP LLP 0.01% of their portfolio | 3.6m $75.1m | Reduced -112.7k |
| STATE STREET CORP 0.00% of their portfolio | 1.9m $39.9m | Reduced -1.5m |
| Palo Alto Investors LP 3.99% of their portfolio | 1.7m $34.4m | Added +2.9k |
| ARMISTICE CAPITAL, LLC 0.84% of their portfolio | 1.6m $32.2m | Added +464.0k |
| VANGUARD GROUP INC 0.00% of their portfolio | 1.2m $24.2m | Added +46.5k |
| JANUS HENDERSON GROUP PLC 0.01% of their portfolio | 1.0m $21.2m | Reduced -283.0k |
| Artal Group S.A. 0.53% of their portfolio | 1.0m $20.7m | Unchanged |
| GEODE CAPITAL MANAGEMENT, LLC 0.00% of their portfolio | 994.3k $20.5m | Added +69.7k |
| DIMENSIONAL FUND ADVISORS LP 0.00% of their portfolio | 861.6k $17.8m | Reduced -1.2k |
| MORGAN STANLEY 0.00% of their portfolio | 810.7k $16.7m | Reduced -1.1m |
| Boxer Capital, LLC 0.75% of their portfolio | 690.0k $14.2m | Unchanged |
| Rock Springs Capital Management LP 0.39% of their portfolio | 625.0k $12.9m | Unchanged |
| JPMORGAN CHASE & CO 0.00% of their portfolio | 591.9k $12.2m | Reduced -4.3k |
| Finepoint Capital LP 2.54% of their portfolio | 433.5k $8.9m | Added +31.1k |
| Birchview Capital, LP 3.89% of their portfolio | 407.1k $8.4m | Added +68.0k |
| NORTHERN TRUST CORP 0.00% of their portfolio | 364.1k $7.5m | Reduced -33.2k |
| CITADEL ADVISORS LLC 0.01% of their portfolio | 353.2k $7.3m | Added +118.2k |
| GOLDMAN SACHS GROUP INC 0.00% of their portfolio | 350.1k $7.2m | Added +41.2k |
| Granahan Investment Management, LLC 0.28% of their portfolio | 335.7k $6.9m | Added +1.7k |
| RENAISSANCE TECHNOLOGIES LLC 0.01% of their portfolio | 329.5k $6.8m | Reduced -60.2k |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC 0.00% of their portfolio | 327.1k $6.8m | Added +8.2k |
| Prosight Management, LP 1.77% of their portfolio | 286.9k $5.9m | Added +116.5k |
| AXA S.A. 0.01% of their portfolio | 241.4k $5.0m | Added +120.8k |
| Mariner, LLC 0.01% of their portfolio | 198.0k $4.1m | Added +21.1k |
| SYSTEMATIC FINANCIAL MANAGEMENT LP 0.12% of their portfolio | 193.8k $4.0m | Added +39.8k |
| Bank of New York Mellon Corp 0.00% of their portfolio | 165.4k $3.4m | Added +19.6k |
| Nuveen Asset Management, LLC 0.00% of their portfolio | 152.4k $3.1m | Reduced -90.7k |
| PINNACLE ASSOCIATES LTD 0.04% of their portfolio | 122.9k $2.5m | Reduced -2.4k |
| JANE STREET GROUP, LLC 0.00% of their portfolio | 121.5k $2.5m | Added +67.1k |
| BANK OF AMERICA CORP /DE/ 0.00% of their portfolio | 118.9k $2.5m | Reduced -121.5k |
| Connor, Clark & Lunn Investment Management Ltd. 0.01% of their portfolio | 112.8k $2.3m | Reduced -19.1k |
| DCF Advisers, LLC 1.16% of their portfolio | 107.5k $2.2m | Added +500 |
| PDT Partners, LLC 0.20% of their portfolio | 102.7k $2.1m | New |
| TD Asset Management Inc 0.00% of their portfolio | 100.7k $2.1m | Reduced -15.6k |
| Rafferty Asset Management, LLC 0.01% of their portfolio | 97.0k $2.0m | Reduced -206.4k |
| MANUFACTURERS LIFE INSURANCE COMPANY, THE 0.00% of their portfolio | 82.9k $1.7m | Added +327 |
| ALGERT GLOBAL LLC 0.05% of their portfolio | 77.2k $1.6m | Added +28.8k |
| TWO SIGMA INVESTMENTS, LP 0.00% of their portfolio | 71.6k $1.5m | New |
| RHUMBLINE ADVISERS 0.00% of their portfolio | 69.8k $1.4m | Added +6.3k |
| Swiss National Bank 0.00% of their portfolio | 68.7k $1.4m | Reduced -10.5k |
| WELLS FARGO & COMPANY/MN 0.00% of their portfolio | 60.7k $1.3m | Added +9.7k |
| NORGES BANK 0.00% of their portfolio | 57.5k $1.2m | Unchanged |
| SG Americas Securities, LLC 0.01% of their portfolio | 54.6k $1.1m | Added +37.9k |
| Thrivent Financial for Lutherans 0.00% of their portfolio | 47.5k $980.0k | Reduced -2.0k |
| ExodusPoint Capital Management, LP 0.01% of their portfolio | 47.1k $972.0k | New |
| ALLIANCEBERNSTEIN L.P. 0.00% of their portfolio | 46.7k $964.8k | Unchanged |
| Walleye Capital LLC 0.01% of their portfolio | 46.1k $951.5k | Added +44.9k |
| RBF Capital, LLC 0.05% of their portfolio | 45.4k $936.3k | Unchanged |
| BARCLAYS PLC 0.00% of their portfolio | 45.3k $935.1k | Reduced -13.0k |
| UBS Group AG 0.00% of their portfolio | 44.8k $924.0k | Reduced -153.9k |
| FEDERATED HERMES, INC. 0.00% of their portfolio | 43.9k $905.3k | New |
| GUGGENHEIM CAPITAL LLC 0.01% of their portfolio | 43.2k $892.6k | Reduced -1.2k |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC 0.00% of their portfolio | 43.1k $889.1k | Reduced -332.1k |
| Jump Financial, LLC 0.02% of their portfolio | 42.8k $883.4k | Added +14.8k |
| ALPS ADVISORS INC 0.01% of their portfolio | 41.9k $865.5k | Added +4.0k |
| Invesco Ltd. 0.00% of their portfolio | 41.1k $848.4k | Added +599 |
| Man Group plc 0.00% of their portfolio | 40.5k $836.5k | Added +10.8k |
| Legal & General Group Plc 0.00% of their portfolio | 38.8k $800.3k | Reduced -101 |
| BNP PARIBAS FINANCIAL MARKETS 0.00% of their portfolio | 38.6k $797.0k | Added +6.4k |
| PRIMECAP MANAGEMENT CO/CA/ 0.00% of their portfolio | 36.5k $753.4k | Unchanged |
| CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM 0.00% of their portfolio | 34.8k $717.6k | Reduced -5.7k |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP 0.00% of their portfolio | 33.8k $697.4k | Reduced -26.2k |
| MILLENNIUM MANAGEMENT LLC 0.00% of their portfolio | 31.3k $645.9k | Reduced -290.9k |
| VOYA INVESTMENT MANAGEMENT LLC 0.00% of their portfolio | 30.9k $637.2k | Reduced -12.8k |
| Cresset Asset Management, LLC 0.00% of their portfolio | 28.3k $584.1k | New |
| DEUTSCHE BANK AG\ 0.00% of their portfolio | 27.6k $568.7k | Reduced -4.3k |
| STATE OF WISCONSIN INVESTMENT BOARD 0.00% of their portfolio | 27.4k $565.6k | Reduced -5.8k |
| TUDOR INVESTMENT CORP ET AL 0.01% of their portfolio | 26.8k $553.0k | New |
| MetLife Investment Management, LLC 0.00% of their portfolio | 25.3k $523.0k | Added +3.5k |
| MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd. 0.00% of their portfolio | 24.8k $511.6k | First filing |
| CITIGROUP INC 0.00% of their portfolio | 24.7k $509.1k | Reduced -235.2k |
| EDGEWOOD MANAGEMENT LLC 0.00% of their portfolio | 24.1k $496.6k | Unchanged |
| HRT FINANCIAL LP 0.00% of their portfolio | 23.4k $483.0k | New |
| Corebridge Financial, Inc. 0.00% of their portfolio | 22.9k $472.2k | First filing |
| Brevan Howard Capital Management LP 0.03% of their portfolio | 21.8k $450.4k | New |
| Ensign Peak Advisors, Inc 0.00% of their portfolio | 21.6k $446.7k | Added +5.0k |
| Y-Intercept (Hong Kong) Ltd 0.02% of their portfolio | 21.4k $440.7k | New |
| Focused Wealth Management, Inc 0.06% of their portfolio | 20.1k $415.5k | Added +10.0k |
| HighTower Advisors, LLC 0.00% of their portfolio | 18.7k $386.0k | Added +102 |
| FOX RUN MANAGEMENT, L.L.C. 0.07% of their portfolio | 18.6k $383.7k | New |
| NEW YORK STATE COMMON RETIREMENT FUND 0.00% of their portfolio | 18.4k $379.3k | Reduced -14.0k |
| PROFUND ADVISORS LLC 0.01% of their portfolio | 18.1k $373.0k | Reduced -28.8k |
| Orion Porfolio Solutions, LLC 0.00% of their portfolio | 16.8k $346.6k | Added +6.6k |
| Orion Portfolio Solutions, LLC 0.00% of their portfolio | 16.8k $346.6k | Added +6.6k |
| HighMark Wealth Management LLC 0.20% of their portfolio | 16.5k $340.6k | Unchanged |
| Amundi 0.00% of their portfolio | 15.9k $319.1k | New |
| Verition Fund Management LLC 0.00% of their portfolio | 15.8k $325.2k | New |
| Handelsbanken Fonder AB 0.00% of their portfolio | 15.4k $318.0k | Added +6.0k |
| STATE BOARD OF ADMINISTRATION OF FLORIDA RETIREMENT SYSTEM 0.00% of their portfolio | 15.4k $317.6k | Added +4.1k |
| SCHRODER INVESTMENT MANAGEMENT GROUP 0.00% of their portfolio | 15.0k $309.6k | Reduced -771 |
| TEACHERS RETIREMENT SYSTEM OF THE STATE OF KENTUCKY 0.00% of their portfolio | 14.0k $290.0k | Unchanged |
| DekaBank Deutsche Girozentrale 0.00% of their portfolio | 14.0k $285.0k | Unchanged |
| STRS OHIO 0.00% of their portfolio | 11.2k $231.2k | Added +1.1k |
| NEOS Investment Management LLC 0.01% of their portfolio | 10.5k $216.9k | New |
| Zurcher Kantonalbank (Zurich Cantonalbank) 0.00% of their portfolio | 10.2k $211.3k | Added +1.2k |
| ARIZONA STATE RETIREMENT SYSTEM 0.00% of their portfolio | 9.8k $201.8k | Reduced -1.3k |