Arrowhead Pharmaceuticals, Inc.
MX ˙ BMV ˙ US04280A1007
SecurityMX:ARWR / Arrowhead Pharmaceuticals, Inc.
InstitutionRenaissance Technologies Llc
ManagerJames Simons
Latest Disclosed Ownership1,036,495 shares
Latest Disclosed Value $ 64,988,237
Renaissance Technologies Llc ownership in ARWR / Arrowhead Pharmaceuticals, Inc.

On May 14, 2026 - Renaissance Technologies Llc filed a 13F-HR form disclosing ownership of 1,036,495 shares of Arrowhead Pharmaceuticals, Inc. (MX:ARWR) valued at $64,988,237 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2025 disclosing 0 shares of Arrowhead Pharmaceuticals, Inc..

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.

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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 ARROWHEAD PHARMACEUTICALS IN COM 04280A100 1,036,495 1,036,495 64,988 0.1017
2025-02-13 2024-12-31 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 0 -231,300 -100.00 0 -100.00
2024-11-13 2024-09-30 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 231,300 231,300 4,480 0.0067
2024-05-13 2024-03-31 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 0 -122,000 -100.00 0 -100.00
2024-02-13 2023-12-31 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 122,000 -259,500 -68.02 4 -70.00 0.0058
2023-11-14 2023-09-30 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 381,500 -3,400 -0.88 10 -23.08 0.0175
2023-08-11 2023-06-30 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 384,900 92,100 31.45 14 85.71 0.0198
2023-05-12 2023-03-31 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 292,800 -201,000 -40.70 7 -65.00 0.0099
2023-02-13 2022-12-31 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 493,800 -261,600 -34.63 20 -99.92 0.0274
2022-11-14 2022-09-30 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 755,400 314,400 71.29 24,966 60.78 0.0353
2022-08-12 2022-06-30 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 441,000 60,700 15.96 15,528 -11.22 0.0184
2022-05-13 2022-03-31 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 380,300 380,300 17,490 0.0205
2022-02-11 2021-12-31 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 0 -54,100 -100.00 0 -100.00
2021-11-12 2021-09-30 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 54,100 -125,100 -69.81 3,377 -77.25 0.0044
2021-08-13 2021-06-30 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 179,200 -62,400 -25.83 14,841 -7.36 0.0185
2021-05-13 2021-03-31 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 241,600 241,600 16,020 0.0199
2020-08-13 2020-06-30 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 0 -666,400 -100.00 0 -100.00
2020-05-14 2020-03-31 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 666,400 -55,900 -7.74 19,172 -58.15 0.0186
2020-02-13 2019-12-31 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 722,300 64,700 9.84 45,815 147.23 0.0352
2019-11-13 2019-09-30 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 657,600 -131,200 -16.63 18,531 -11.35 0.0157
2019-08-12 2019-06-30 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 788,800 618,400 362.91 20,903 568.47 0.0184
2019-05-14 2019-03-31 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 170,400 170,400 3,127 0.0028
2017-11-13 2017-09-30 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 0 -374,164 -100.00 0 -100.00
2017-08-11 2017-06-30 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 374,164 374,164 606 0.0008
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.