Alkermes plc
US ˙ NasdaqGS ˙ IE00B56GVS15

SecurityALKS / Alkermes plc
InstitutionState Street Corp
Latest Disclosed Ownership8,540,351 shares
Ownership 5.20%
State Street Corp ownership in ALKS / Alkermes plc

2025-11-10 - State Street Corp has filed an SCHEDULE 13G form with the Securities and Exchange Commission (SEC) disclosing ownership of 8,540,351 shares of Alkermes plc (US:ALKS). This represents 5.2 percent ownership of the company. In their previous filing dated 2025-05-13 , State Street Corp had reported owning 8,022,670 shares, indicating an increase of 6.45 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)
2025-11-10 2025-11-10 13G 8,022,670 8,540,351 6.45 5.20 6.12
2025-05-13 2025-05-13 13G 9,352,970 8,022,670 -14.22 4.90 -12.50
2024-01-24 2024-01-24 13G 9,352,970 5.60

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 ALKERMES SHS G01767105 9,465,286 -7,572 -0.08 334,693 26.28 0.0116
2026-02-13 2025-12-31 13F ALKERMES SHS G01767105 9,472,858 932,507 10.92 265,051 3.45 0.0089
2025-11-14 2025-09-30 13F ALKERMES SHS G01767105 8,540,351 332,095 4.05 256,211 9.10 0.0089
2025-08-14 2025-06-30 13F ALKERMES SHS G01767105 8,208,256 185,586 2.31 234,838 -11.35 0.0088
2025-05-15 2025-03-31 13F ALKERMES SHS G01767105 8,022,670 -792,305 -8.99 264,909 4.49 0.0109
2025-02-14 2024-12-31 13F ALKERMES SHS G01767105 8,814,975 -370,417 -4.03 253,519 -1.39 0.0100
2024-11-14 2024-09-30 13F ALKERMES SHS G01767105 9,185,392 -29,666 -0.32 257,099 15.77 0.0105
2024-08-14 2024-06-30 13F ALKERMES SHS G01767105 9,215,058 211,145 2.35 222,083 -8.88 0.0097
2024-05-15 2024-03-31 13F ALKERMES SHS G01767105 9,003,913 -349,057 -3.73 243,736 -6.06 0.0109
2024-02-14 2023-12-31 13F ALKERMES SHS G01767105 9,352,970 3,261,476 53.54 259,451 52.06 0.0126
2023-11-14 2023-09-30 13F ALKERMES SHS G01767105 6,091,494 201,191 3.42 170,623 -7.45 0.0095
2023-08-14 2023-06-30 13F ALKERMES SHS G01767105 5,890,303 103,262 1.78 184,366 13.01 0.0097
2023-05-15 2023-03-31 13F ALKERMES SHS G01767105 5,787,041 -672,366 -10.41 163,137 -3.35 0.0092
2023-05-15 2022-12-31 13F/A-99 ALKERMES SHS G01767105 6,459,407 -7,794 -0.12 168,784 16.88 0.0099
2023-05-15 2022-12-31 13F ALKERMES SHS G01767105 6,459,407 -7,794 168,784 0.0099
2022-11-15 2022-09-30 13F ALKERMES SHS G01767105 6,467,201 556,097 9.41 144,413 -17.99 0.0091
2022-08-15 2022-06-30 13F ALKERMES SHS G01767105 5,911,104 131,205 2.27 176,092 15.80 0.0106
2022-05-16 2022-03-31 13F ALKERMES SHS G01767105 5,779,899 85,459 1.50 152,069 14.81 0.0075
2022-02-14 2021-12-31 13F ALKERMES SHS G01767105 5,694,440 772,964 15.71 132,453 -12.73 0.0063
2021-11-15 2021-09-30 13F ALKERMES SHS G01767105 4,921,476 -32,860 -0.66 151,778 24.94 0.0080
2021-08-16 2021-06-30 13F ALKERMES SHS G01767105 4,954,336 459,735 10.23 121,480 44.69 0.0064
2021-07-09 2021-03-31 13F/A-1 ALKERMES SHS G01767105 4,494,601 -367,827 -7.56 83,959 -13.45 0.0048
2021-05-17 2021-03-31 13F ALKERMES SHS G01767105 4,494,601 -367,827 83,959 0.0048
2021-02-16 2020-12-31 13F ALKERMES SHS G01767105 4,862,428 163,689 3.48 97,005 24.59 0.0059
2020-11-10 2020-09-30 13F ALKERMES SHS G01767105 4,698,739 -509,926 -9.79 77,858 -22.97 0.0053
2020-08-14 2020-06-30 13F ALKERMES SHS G01767105 5,208,665 470,866 9.94 101,074 47.94 0.0073
2020-06-19 2020-03-31 13F/A-1 ALKERMES SHS G01767105 4,737,799 86,938 1.87 68,319 -27.99 0.0060
2020-05-11 2020-03-31 13F ALKERMES SHS G01767105 4,737,799 68,319
2020-02-06 2019-12-31 13F ALKERMES SHS G01767105 4,650,861 -671,347 -12.61 94,878 -8.63 0.0065
2019-11-14 2019-09-30 13F ALKERMES SHS G01767105 5,322,208 -597,794 -10.10 103,836 -22.18 0.0077
2019-08-14 2019-06-30 13F ALKERMES SHS G01767105 5,920,002 938,795 18.85 133,437 -26.59 0.0099
2019-05-15 2019-03-31 13F ALKERMES SHS G01767105 4,981,207 395,168 8.62 181,764 34.31 0.0142
2019-02-12 2018-12-31 13F ALKERMES SHS G01767105 4,586,039 17,451 0.38 135,334 -30.20 0.0123
2018-11-09 2018-09-30 13F ALKERMES Common equity shares G01767105 4,568,588 450,532 10.94 193,891 14.39 0.0149
2018-08-14 2018-06-30 13F ALKERMES Common equity shares G01767105 4,118,056 86,914 2.16 169,505 -27.45 0.0142
2018-05-15 2018-03-31 13F ALKERMES Common equity shares G01767105 4,031,142 -4,708 -0.12 233,647 5.78 0.0198
2018-02-14 2017-12-31 13F ALKERMES Common equity shares G01767105 4,035,850 -330,059 -7.56 220,881 -0.49 0.0178
2017-11-14 2017-09-30 13F ALKERMES Common equity shares G01767105 4,365,909 431,112 10.96 221,970 -2.69 0.0192
2017-08-14 2017-06-30 13F ALKERMES Common equity shares G01767105 3,934,797 -39,205 -0.99 228,106 -1.88 0.0202
2017-05-15 2017-03-31 13F ALKERMES Common equity shares G01767105 3,974,002 228,719 6.11 232,480 11.68 0.0207
2017-02-09 2016-12-31 13F ALKERMES Common equity shares G01767105 3,745,283 74,500 2.03 208,160 20.58 0.0196
2017-01-13 2016-09-30 13F/A-1 ALKERMES Common equity shares G01767105 3,670,783 -12,849 -0.35 172,635 8.43 0.0174
2016-11-14 2016-09-30 13F ALKERMES Common equity shares G01767105 3,657,096 171,991
2016-08-12 2016-06-30 13F ALKERMES Common equity shares G01767105 3,683,632 -42,979 -1.15 159,219 24.96 0.0171
2016-05-20 2016-03-31 13F/A-1 ALKERMES Common equity shares G01767105 3,726,611 720,887 23.98 127,418 -46.60 0.0138
2016-05-12 2016-03-31 13F ALKERMES Common equity shares G01767105 3,726,611 127,418
2016-02-16 2015-12-31 13F ALKERMES Common equity shares G01767105 3,005,724 125,997 4.38 238,600 41.23 0.0261
2015-11-16 2015-09-30 13F ALKERMES Common equity shares G01767105 2,879,727 163,021 6.00 168,947 -3.34 0.0197
2015-08-13 2015-06-30 13F ALKERMES Common equity shares G01767105 2,716,706 149,840 5.84 174,790 11.69 0.0187
2015-05-15 2015-03-31 13F ALKERMES Common equity shares G01767105 2,566,866 755,288 41.69 156,502 47.52 0.0161
2015-02-11 2014-12-31 13F ALKERMES Common equity shares G01767105 1,811,578 -49,939 -2.68 106,086 32.93 0.0106
2014-11-12 2014-09-30 13F/A-1 ALKERMES Common equity shares G01767105 1,861,517 43,935 2.42 79,804 -12.76 0.0086
2014-11-10 2014-09-30 13F ALKERMES Common equity shares G01767105 1,861,517 79,804
2014-08-12 2014-06-30 13F ALKERMES Common equity shares G01767105 1,817,582 -31,631 -1.71 91,477 12.20 0.0099
2014-05-15 2014-03-31 13F/A-1 ALKERMES Common equity shares G01767105 1,849,213 106,976 6.14 81,529 15.09 0.0093
2014-05-13 2014-03-31 13F ALKERMES Common equity shares G01767105 1,850,656 81,593
2014-02-06 2013-12-31 13F/A-1 ALKERMES Common equity shares G01767105 1,742,237 -235,493 -11.91 70,840 6.54 0.0079
2014-02-06 2013-12-31 13F ALKERMES Common equity shares G01767105 3,471,989 64,300
2013-11-12 2013-09-30 13F ALKERMES Common equity shares G01767105 1,977,730 -40,768 -2.02 66,491 14.86 0.0082
2013-08-08 2013-06-30 13F ALKERMES Common equity shares G01767105 2,018,498 2,018,498 57,890 0.0075
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.