Alkermes plc
US ˙ NasdaqGS ˙ IE00B56GVS15

SecurityALKS / Alkermes plc
InstitutionRockefeller Capital Management L.P.
Latest Disclosed Ownership2,566 shares
Latest Disclosed Value $ 90,733
Rockefeller Capital Management L.P. reports 81.86% increase in ownership of ALKS / Alkermes plc

On May 14, 2026 - Rockefeller Capital Management L.P. filed a 13F-HR form disclosing ownership of 2,566 shares of Alkermes plc (US:ALKS) valued at $90,734 USD as of March 31, 2026. The entity filed a previous 13F-HR/A on March 16, 2026 disclosing 1,411 shares of Alkermes plc. This represents a change in shares of 81.86% during the quarter. The current value of the position is $109,722 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)
2026-05-14 2026-03-31 13F ALKERMES SHS G01767105 2,566 1,155 81.86 91 130.77 0.0002
2026-03-16 2025-12-31 13F/A-1 ALKERMES SHS G01767105 1,411 -746 -34.59 39 -39.06 0.0001
2026-02-14 2025-12-31 13F ALKERMES SHS G01767105 1,411 -746 39 0.0000
2025-11-14 2025-09-30 13F ALKERMES SHS G01767105 2,157 2,157 65 0.0001
2023-05-17 2023-03-31 13F ALKERMES SHS G01767105 0 -46 -100.00 0 -100.00
2023-03-06 2022-12-31 13F ALKERMES SHS G01767105 46 -340 -88.08 1 -87.50 0.0000
2022-11-02 2022-09-30 13F ALKERMES SHS G01767105 386 33 9.35 8 -20.00 0.0000
2022-08-12 2022-06-30 13F ALKERMES SHS G01767105 353 -30 -7.83 10 0.00 0.0001
2022-05-13 2022-03-31 13F ALKERMES SHS G01767105 383 383 10 0.0000
2021-11-12 2021-09-30 13F ALKERMES SHS G01767105 0 -351 -100.00 0 -100.00
2021-08-10 2021-06-30 13F ALKERMES SHS G01767105 351 259 281.52 8 700.00 0.0000
2021-05-11 2021-03-31 13F ALKERMES SHS G01767105 92 92 1 0.0000
2019-05-10 2019-03-31 13F ALKERMES SHS G01767105 0 -1,850 -100.00 0 -100.00
2019-02-12 2018-12-31 13F ALKERMES SHS G01767105 1,850 0 0.00 55 -30.38 0.0010
2018-11-02 2018-09-30 13F Alkermes Common G01767105 1,850 0 0.00 79 3.95 0.0012
2018-07-31 2018-06-30 13F Alkermes Common G01767105 1,850 0 0.00 76 -28.97 0.0012
2018-05-09 2018-03-31 13F Alkermes Common G01767105 1,850 1,850 107 0.0018
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.