Arrowhead Pharmaceuticals, Inc.
US ˙ NasdaqGS ˙ US04280A1007

SecurityARWR / Arrowhead Pharmaceuticals, Inc.
InstitutionState Street Corp
Latest Disclosed Ownership6,371,056 shares
Ownership 4.60%
State Street Corp ownership in ARWR / Arrowhead Pharmaceuticals, Inc.

2025-08-11 - State Street Corp has filed an SCHEDULE 13G form with the Securities and Exchange Commission (SEC) disclosing ownership of 6,371,056 shares of Arrowhead Pharmaceuticals, Inc. (US:ARWR). This represents 4.6 percent ownership of the company. In their previous filing dated 2025-05-13 , State Street Corp had reported owning 6,999,249 shares, indicating a decrease of -8.98 percent.

Institutional Ownership: 13D/G Filings

This table shows a history of the 13D/G filings made by the investor and/or investor group. Note that the share values in this table are not directly comparable to any numbers shown in the 13F table (if any).

File
Date		Effective
Date		Form Prev
Shares		 Latest
Shares		 ΔShares
(Percent)		 Ownership
(Percent)		 ΔOwnership
(Percent)
2025-08-11 2025-08-11 13G 6,999,249 6,371,056 -8.98 4.60 -9.80
2025-05-13 2025-05-13 13G 6,016,227 6,999,249 16.34 5.10 6.25
2025-02-05 2025-02-05 13G 6,354,331 6,016,227 -5.32 4.80 -5.88
2024-10-16 2024-10-16 13G/A 6,825,111 6,354,331 -6.90 5.10 -19.69
2024-01-24 2024-01-24 13G/A 5,970,344 6,825,111 14.32 6.35 12.79
2023-02-08 2023-02-08 13G/A 4,124,470 5,970,344 44.75 5.63 36.65
2020-02-13 2020-02-13 13G/A 5,073,775 4,124,470 -18.71 4.12 -25.09
2019-02-13 2019-02-13 13G 5,073,775 5.50

Important Note: One of the primary uses of the 13D/G filings is to evaluate the ability of a firm to control a company (ie, the "beneficial ownership"). To that end, firms are required to report not just direct holdings in companies, but indirect holdings that they control. For investment firms, these indirect holdings can include shares in funds they manage, advisory accounts, and in the case of activist campaigns, pledged votes. Therefore, share counts listed in 13D/G filings can differ significantly than share counts listed in 13F filings.

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 6,496,130 92,300 1.44 407,307 -4.20 0.0141
2026-02-13 2025-12-31 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 6,403,830 6,466 0.10 425,150 92.69 0.0143
2025-11-14 2025-09-30 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 6,397,364 26,308 0.41 220,645 119.19 0.0077
2025-08-14 2025-06-30 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 6,371,056 -628,193 -8.98 100,663 12.89 0.0038
2025-05-15 2025-03-31 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 6,999,249 983,022 16.34 89,170 -21.16 0.0037
2025-02-14 2024-12-31 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 6,016,227 -338,104 -5.32 113,105 -8.11 0.0045
2024-11-14 2024-09-30 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 6,354,331 516,569 8.85 123,083 -18.88 0.0050
2024-08-14 2024-06-30 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 5,837,762 -722,941 -11.02 151,723 -19.14 0.0066
2024-05-15 2024-03-31 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 6,560,703 -264,408 -3.87 187,636 -10.16 0.0084
2024-02-14 2023-12-31 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 6,825,111 962,146 16.41 208,848 32.57 0.0102
2023-11-14 2023-09-30 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 5,862,965 355,394 6.45 157,538 -19.79 0.0087
2023-08-14 2023-06-30 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 5,507,571 -395,197 -6.70 196,400 30.99 0.0103
2023-05-15 2023-03-31 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 5,902,768 -67,576 -1.13 149,930 -38.09 0.0085
2023-05-15 2022-12-31 13F/A-99 ARROWHEAD PHARMACEUTICALS IN COM 04280A100 5,970,344 715,912 13.62 242,157 39.44 0.0142
2023-05-15 2022-12-31 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 5,970,344 715,912 242,157 0.0142
2022-11-15 2022-09-30 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 5,254,432 -328,314 -5.88 173,659 -11.65 0.0110
2022-08-15 2022-06-30 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 5,582,746 900,791 19.24 196,568 -8.71 0.0118
2022-05-16 2022-03-31 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 4,681,955 777,184 19.90 215,323 -16.83 0.0106
2022-02-14 2021-12-31 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 3,904,771 -26,397 -0.67 258,886 5.49 0.0123
2021-11-15 2021-09-30 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 3,931,168 344,837 9.62 245,423 -17.37 0.0130
2021-08-16 2021-06-30 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 3,586,331 -147,789 -3.96 297,020 19.96 0.0157
2021-07-09 2021-03-31 13F/A-1 ARROWHEAD PHARMACEUTICALS IN COM 04280A100 3,734,120 -197,895 -5.03 247,609 -17.93 0.0142
2021-05-17 2021-03-31 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 3,734,120 -197,895 247,609 0.0142
2021-02-16 2020-12-31 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 3,932,015 -611,109 -13.45 301,704 54.22 0.0185
2020-11-10 2020-09-30 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 4,543,124 -348,323 -7.12 195,627 -7.40 0.0134
2020-08-14 2020-06-30 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 4,891,447 596,773 13.90 211,262 70.98 0.0154
2020-06-19 2020-03-31 13F/A-1 ARROWHEAD PHARMACEUTICALS IN COM 04280A100 4,294,674 170,204 4.13 123,558 -52.77 0.0108
2020-05-11 2020-03-31 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 4,294,674 170,204 123,558 10,850.8803
2020-02-06 2019-12-31 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 4,124,470 -760,166 -15.56 261,615 90.06 0.0179
2019-11-14 2019-09-30 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 4,884,636 157,101 3.32 137,649 9.87 0.0103
2019-08-14 2019-06-30 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 4,727,535 22,938 0.49 125,280 45.12 0.0093
2019-05-15 2019-03-31 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 4,704,597 -369,178 -7.28 86,329 37.00 0.0067
2019-02-12 2018-12-31 13F ARROWHEAD PHARMACEUTICALS IN COM 04280A100 5,073,775 139,022 2.82 63,016 -33.39 0.0057
2018-11-09 2018-09-30 13F ARROWHEAD PHARMACEUTICALS Common equity shares 04280A100 4,934,753 902,897 22.39 94,603 72.53 0.0073
2018-08-14 2018-06-30 13F ARROWHEAD PHARMACEUTICALS Common equity shares 04280A100 4,031,856 1,478,425 57.90 54,832 197.82 0.0046
2018-05-15 2018-03-31 13F ARROWHEAD PHARMACEUTICALS Common equity shares 04280A100 2,553,431 2,441,760 2,186.57 18,411 4,368.69 0.0016
2018-02-14 2017-12-31 13F ARROWHEAD PHARMACEUTICALS Common equity shares 04280A100 111,671 55,031 97.16 412 68.16 0.0000
2017-11-14 2017-09-30 13F ARROWHEAD PHARMACEUTICALS Common equity shares 04280A100 56,640 -10,000 -15.01 245 128.97 0.0000
2017-08-14 2017-06-30 13F ARROWHEAD PHARMACEUTICALS Common equity shares 04280A100 66,640 -1,077,026 -94.17 107 -94.94 0.0000
2017-05-15 2017-03-31 13F ARROWHEAD PHARMACEUTICALS Common equity shares 04280A100 1,143,666 178,638 18.51 2,115 41.38 0.0002
2017-02-09 2016-12-31 13F ARROWHEAD PHARMACEUTICALS Common equity shares 04280A100 965,028 -426,804 -30.66 1,496 -85.38 0.0001
2017-01-13 2016-09-30 13F/A-1 ARROWHEAD PHARMACEUTICALS Common equity shares 04280A100 1,391,832 434,296 45.36 10,233 100.80 0.0010
2016-11-14 2016-09-30 13F ARROWHEAD PHARMACEUTICALS Common equity shares 04280A100 1,391,832 10,233
2016-08-12 2016-06-30 13F ARROWHEAD PHARMACEUTICALS Common equity shares 04280A100 957,536 12,676 1.34 5,096 11.98 0.0005
2016-05-20 2016-03-31 13F/A-1 ARROWHEAD PHARMACEUTICALS Common equity shares 04280A100 944,860 944,860 4,551 0.0005
2016-05-12 2016-03-31 13F ARROWHEAD PHARMACEUTICALS Common equity shares 04280A100 944,860 4,551 0.0005
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.