Prothena Corporation plc
DE ˙ DB ˙ IE00B91XRN20
7,74 € ↑0,39 (5,30%)
2026-06-04
DEL PRIS
SecurityDE:0PT / Prothena Corporation plc
InstitutionNorthern Trust Corp
Latest Disclosed Ownership369,542 shares
Latest Disclosed Value $ 3,591,948
Northern Trust Corp reports 1.73% increase in ownership of 0PT / Prothena Corporation plc

On May 14, 2026 - Northern Trust Corp filed a 13F-HR form disclosing ownership of 369,542 shares of Prothena Corporation plc (DE:0PT) valued at $3,030,244 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 363,241 shares of Prothena Corporation plc. This represents a change in shares of 1.73% during the quarter. The current value of the position is $2,861,733 USD.

Institutional Ownership: 13F and NPORT Filings

The Security and Class in the table below are shown exactly as filed by the investor. We do our best to track continuity of investments through acquisitions, and this will be reflected in the table as changes in names. In addition to descriptive data, performance of the investment is shown over time. To calculate quarterly performance, we first calculate cost basis of the shares purchased during the quarter, then use that to calculate gross profit. Quarterly return is Gross Profit / Starting Portfolio value.

Note that cost basis is calculated and stored in thousands, so small quarterly changes in shares frequently result in a cost basis of zero.

Upgrade to unlock premium data and export to Excel .

Disclosed Equity Positions (from 13F/NPORT Filings)
File
Date		 Effective
Date		Form Security Class ID Avg Price
Paid (Est)		 Reported
Shares		 ΔShares ΔShares
(%)		 Reported
Value
(x1000)		 ΔValue
(%)		 Alloc
(%)		 ΔAlloc ΔAlloc (%) Cost Basis
(x1000)		 Unrealized
Gain/Loss
(x1000)
2026-05-14 2026-03-31 13F PROTHENA CORP SHS G72800108 369,542 6,301 1.73 3,592 3.55 0.0001
2026-02-17 2025-12-31 13F PROTHENA CORP SHS G72800108 363,241 28,584 8.54 3,469 6.18 0.0001
2025-11-14 2025-09-30 13F PROTHENA CORP SHS G72800108 334,657 103 0.03 3,266 60.89 0.0001
2025-08-13 2025-06-30 13F PROTHENA CORP SHS G72800108 334,554 -39,149 -10.48 2,031 -56.10 0.0003
2025-05-13 2025-03-31 13F PROTHENA CORP SHS G72800108 373,703 -30,793 -7.61 4,625 -17.46 0.0007
2025-02-14 2024-12-31 13F PROTHENA CORP SHS G72800108 404,496 31,841 8.54 5,602 -10.14 0.0008
2024-11-13 2024-09-30 13F PROTHENA CORP COM G72800108 372,655 8,549 2.35 6,235 -17.05 0.0010
2024-08-14 2024-06-30 13F PROTHENA CORP COM G72800108 364,106 -33,157 -8.35 7,515 -23.63 0.0013
2024-05-14 2024-03-31 13F PROTHENA CORP COM G72800108 397,263 -6,847 -1.69 9,840 -32.99 0.0017
2024-02-13 2023-12-31 13F PROTHENA CORP COM G72800108 404,110 -5,737 -1.40 14,685 -25.74 0.0027
2023-11-13 2023-09-30 13F PROTHENA CORP COM G72800108 409,847 -2,128 -0.52 19,775 -29.70 0.0038
2023-08-11 2023-06-30 13F PROTHENA CORP COM G72800108 411,975 29,287 7.65 28,130 51.66 0.0054
2023-05-15 2023-03-31 13F PROTHENA CORP COM G72800108 382,688 21,103 5.84 18,549 -14.86 0.0037
2023-02-13 2022-12-31 13F PROTHENA CORP COM G72800108 361,585 14,437 4.16 21,785 3.50 0.0046
2022-11-14 2022-09-30 13F PROTHENA CORP COM G72800108 347,148 -5,073 -1.44 21,048 120.10 0.0048
2022-08-12 2022-06-30 13F PROTHENA CORP COM G72800108 352,221 -12,571 -3.45 9,563 -28.31 0.0020
2022-05-13 2022-03-31 13F PROTHENA CORP COM G72800108 364,792 -80,027 -17.99 13,339 -39.30 0.0023
2022-02-08 2021-12-31 13F PROTHENA CORP COM G72800108 444,819 3,834 0.87 21,974 -30.04 0.0036
2021-11-15 2021-09-30 13F PROTHENA CORP COM G72800108 440,985 -299 -0.07 31,411 38.45 0.0056
2021-08-13 2021-06-30 13F PROTHENA CORP SHS G72800108 441,284 100,009 29.30 22,687 164.63 0.0040
2021-05-12 2021-03-31 13F PROTHENA CORP SHS G72800108 341,275 -28,885 -7.80 8,573 92.87 0.0016
2021-02-11 2020-12-31 13F PROTHENA CORP SHS G72800108 370,160 -16,467 -4.26 4,445 15.07 0.0009
2020-11-16 2020-09-30 13F PROTHENA CORP SHS G72800108 386,627 -44,714 -10.37 3,863 -14.38 0.0008
2020-08-14 2020-06-30 13F PROTHENA CORP COM G72800108 431,341 -83,505 -16.22 4,512 -18.10 0.0011
2020-05-14 2020-03-31 13F PROTHENA CORP SHS G72800108 514,846 -20 -0.00 5,509 -32.40 0.0016
2020-02-14 2019-12-31 13F PROTHENA CORP SHS G72800108 514,866 20,816 4.21 8,150 110.43 0.0018
2019-11-13 2019-09-30 13F PROTHENA CORP COM G72800108 494,050 -26,761 -5.14 3,873 -29.63 0.0009
2019-08-13 2019-06-30 13F PROTHENA CORP SHS G72800108 520,811 35,777 7.38 5,504 -6.44 0.0013
2019-05-13 2019-03-31 13F PROTHENA CORP SHS G72800108 485,034 -1,090 -0.22 5,883 17.50 0.0015
2019-02-12 2018-12-31 13F PROTHENA CORP SHS G72800108 486,124 -9,136 -1.84 5,007 -22.71 0.0014
2018-11-14 2018-09-30 13F PROTHENA CORP SHS G72800108 495,260 36,018 7.84 6,478 -3.26 0.0016
2018-09-18 2018-06-30 13F/A-1 PROTHENA CORP SHS G72800108 459,242 -39 -0.01 6,696 -60.28 0.0017
2018-08-14 2018-06-30 13F PROTHENA CORP SHS G72800108 461,279 1,998 6,726
2018-05-09 2018-03-31 13F PROTHENA CORP SHS G72800108 459,281 2,983 0.65 16,859 -1.44 0.0044
2018-02-14 2017-12-31 13F PROTHENA CORP SHS G72800108 456,298 -1,536 -0.34 17,106 -42.31 0.0043
2017-11-13 2017-09-30 13F PROTHENA CORP SHS G72800108 457,834 55,023 13.66 29,653 36.02 0.0077
2017-08-11 2017-06-30 13F PROTHENA CORP COM G72800108 402,811 -19,680 -4.66 21,801 -7.51 0.0061
2017-05-12 2017-03-31 13F PROTHENA CORP COM G72800108 422,491 27,063 6.84 23,572 21.18 0.0068
2017-02-13 2016-12-31 13F PROTHENA CORP COM G72800108 395,428 2,616 0.67 19,452 -17.43 0.0060
2016-11-09 2016-09-30 13F PROTHENA CORP COM G72800108 392,812 -1,538 -0.39 23,557 70.88 0.0073
2016-08-12 2016-06-30 13F PROTHENA CORP COM G72800108 394,350 8,349 2.16 13,786 -13.22 0.0045
2016-08-19 2016-03-31 13F/A-1 PROTHENA CORP COM G72800108 386,001 33,030 9.36 15,887 -33.92 0.0053
2016-05-13 2016-03-31 13F PROTHENA CORP COM G72800108 386,001 15,887
2016-02-12 2015-12-31 13F PROTHENA CORP COM G72800108 352,971 -135,369 -27.72 24,041 8.58 0.0080
2015-11-12 2015-09-30 13F PROTHENA CORP COM G72800108 488,340 488,340 0.00 22,141 0.0074
2015-08-13 2015-06-30 13F PROTHENA CORP COM G72800108 0 -424,632 -100.00 0 -100.00
2015-05-14 2015-03-31 13F PROTHENA CORP COM G72800108 424,632 14,215 3.46 16,194 90.07 0.0049
2015-02-12 2014-12-31 13F PROTHENA CORP COM G72800108 410,417 14,616 3.69 8,520 -2.85 0.0026
2014-11-13 2014-09-30 13F PROTHENA CORP COM G72800108 395,801 215,243 119.21 8,770 115.43 0.0028
2014-08-14 2014-06-30 13F PROTHENA CORP COM G72800108 180,558 -11,144 -5.81 4,071 -44.57 0.0013
2014-05-14 2014-03-31 13F PROTHENA CORP COM G72800108 191,702 -6,068 -3.07 7,344 40.05 0.0023
2014-02-21 2013-12-31 13F/A-1 PROTHENA CORP COM G72800108 197,770 44,065 28.67 5,244 68.67 0.0017
2014-02-12 2013-12-31 13F PROTHENA CORP COM G72800108 197,770 5,244
2013-11-13 2013-09-30 13F PROTHENA CORP COM G72800108 153,705 100,268 187.64 3,109 349.93 0.0011
2013-08-09 2013-06-30 13F PROTHENA CORP COM G72800108 53,437 53,437 691 0.0003
Legend
Shares
The total number of shares held by the institution at the end of the reporting period (the effective date). This is provided in the filing.
Value
The total value of the shares as of the effective date. This is provided in the filing.
Avg. Share Price
The weighted average share price of the shares held by the institution. We use FIFO accounting to determine this price
Class
This is the security class as indicated by the filer. There are a variety of values for this field. Common values include "EC" = equity common, "EP" - equity preferred
Allocation (%)
The percent of the institution's portfolio that this position represents. This is provided in NPORT filings. For 13F filings, we calculate it.
Change in Allocation
The change in allocation from the prior reporting period. This is calculated as current allocation - prior allocation.
Change in Allocation (%)
The percent change in allocation from the prior reporting period. This is calculated as (current allocation - prior allocation) / prior allocation.
Cost Basis
The total cost of the shares held. This is calculated as reported shares * avg. share price
Unrealized Gain/Loss
This is the market value of the position as of the effective date minus the cost basis.