Arrowhead Pharmaceuticals, Inc.
US ˙ NasdaqGS ˙ US04280A1007

SecurityARWR / Arrowhead Pharmaceuticals, Inc.
InstitutionAlliancebernstein L.p.
Latest Disclosed Ownership280,394 shares
Latest Disclosed Value $ 18,615,358
Alliancebernstein L.p. reports 62.39% increase in ownership of ARWR / Arrowhead Pharmaceuticals, Inc.

On May 15, 2026 - Alliancebernstein L.p. filed a 13F-HR form disclosing ownership of 280,394 shares of Arrowhead Pharmaceuticals, Inc. (US:ARWR) valued at $17,580,704 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 172,666 shares of Arrowhead Pharmaceuticals, Inc.. This represents a change in shares of 62.39% during the quarter. The current value of the position is $21,075,815 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.

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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)
2026-05-15 2026-03-31 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 280,394 107,728 62.39 18,615 62.39 0.0050
2026-02-17 2025-12-31 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 172,666 16,772 10.76 11,463 113.23 0.0036
2025-11-14 2025-09-30 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 155,894 -3,176 -2.00 5,377 113.93 0.0017
2025-08-14 2025-06-30 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 159,070 4,300 2.78 2,513 27.50 0.0008
2025-05-15 2025-03-31 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 154,770 -110,712 -41.70 1,972 -60.51 0.0007
2025-02-12 2024-12-31 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 265,482 -441 -0.17 4,991 -3.09 0.0017
2024-11-14 2024-09-30 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 265,923 -9,156 -3.33 5,151 -27.96 0.0017
2024-08-14 2024-06-30 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 275,079 31,226 12.81 7,149 2.51 0.0025
2024-05-14 2024-03-31 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 243,853 18,128 8.03 6,974 0.97 0.0025
2024-02-14 2023-12-31 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 225,725 -1,071 -0.47 6,907 13.34 0.0027
2023-11-14 2023-09-30 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 226,796 -4,549 -1.97 6,094 -26.12 0.0026
2023-08-15 2023-06-30 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 231,345 -71,841 -23.70 8,250 7.13 0.0034
2023-05-15 2023-03-31 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 303,186 -2,281,507 -88.27 7,701 -92.66 0.0033
2023-02-15 2022-12-31 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 2,584,693 117,633 4.77 104,835 28.58 0.0472
2022-11-15 2022-09-30 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 2,467,060 -331,074 -11.83 81,536 -17.24 0.0395
2022-08-15 2022-06-30 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 2,798,134 41,803 1.52 98,522 -22.28 0.0450
2022-05-13 2022-03-31 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 2,756,331 291,820 11.84 126,764 -22.42 0.0489
2022-02-14 2021-12-31 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 2,464,511 1,494,218 154.00 163,397 169.74 0.0578
2021-11-10 2021-09-30 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 970,293 -146,587 -13.12 60,575 -34.51 0.0239
2021-07-30 2021-06-30 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 1,116,880 50,883 4.77 92,500 30.86 0.0371
2021-05-06 2021-03-31 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 1,065,997 760,005 248.37 70,686 201.06 0.0310
2021-02-08 2020-12-31 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 305,992 -12,560 -3.94 23,479 71.17 0.0111
2020-11-12 2020-09-30 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 318,552 -36,718 -10.34 13,717 -10.60 0.0074
2020-08-13 2020-06-30 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 355,270 31,960 9.89 15,344 64.95 0.0090
2020-05-14 2020-03-31 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 323,310 -6,810 -2.06 9,302 -55.58 0.0067
2020-02-18 2019-12-31 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 330,120 83,850 34.05 20,940 201.73 0.0119
2019-11-14 2019-09-30 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 246,270 -20,100 -7.55 6,940 -1.69 0.0043
2019-08-14 2019-06-30 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 266,370 154,998 139.17 7,059 245.35 0.0044
2019-05-14 2019-03-31 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 111,372 -18,328 -14.13 2,044 26.88 0.0013
2019-02-13 2018-12-31 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 129,700 0 0.00 1,611 -35.20 0.0012
2018-11-08 2018-09-30 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 129,700 26,700 25.92 2,486 77.44 0.0016
2018-08-13 2018-06-30 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 103,000 103,000 1,401 0.0010
2017-08-10 2017-06-30 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 0 -77,900 -100.00 0 -100.00
2017-05-11 2017-03-31 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 77,900 -4,200 -5.12 144 13.39 0.0001
2017-02-13 2016-12-31 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 82,100 10,800 15.15 127 -75.76 0.0001
2016-11-10 2016-09-30 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 71,300 0 0.00 524 38.26 0.0004
2016-08-11 2016-06-30 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 71,300 71,300 379 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.