Alkermes plc
US ˙ NasdaqGS ˙ IE00B56GVS15

SecurityALKS / Alkermes plc
InstitutionProsight Management, LP
Latest Disclosed Ownership513,632 shares
Latest Disclosed Value $ 18,162,028
Prosight Management, LP ownership in ALKS / Alkermes plc

On May 15, 2026 - Prosight Management, LP filed a 13F-HR form disclosing ownership of 513,632 shares of Alkermes plc (US:ALKS) valued at $18,162,028 USD as of March 31, 2026. The entity filed a previous 13F-HR on November 14, 2024 disclosing 0 shares of Alkermes plc. The current value of the position is $21,962,904 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.

Upgrade to unlock premium data and export to Excel .

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 513,632 513,632 18,162 2.9783
2024-11-14 2024-09-30 13F ALKERMES SHS G01767105 0 -275,000 -100.00 0 -100.00
2024-08-14 2024-06-30 13F ALKERMES SHS G01767105 275,000 60,000 27.91 6,628 13.87 1.9809
2024-05-15 2024-03-31 13F ALKERMES SHS G01767105 215,000 200,000 1,333.33 5,820 1,299.04 1.6191
2024-02-14 2023-12-31 13F ALKERMES SHS G01767105 15,000 -50,000 -76.92 416 -77.14 0.1671
2023-11-14 2023-09-30 13F ALKERMES SHS G01767105 65,000 -82,554 -55.95 1,821 -60.59 0.5770
2023-08-14 2023-06-30 13F/A-1 ALKERMES SHS G01767105 147,554 -168,611 -53.33 4,618 -48.18 1.3519
2023-08-14 2023-06-30 13F ALKERMES SHS G01767105 147,554 -168,611 4,618 1.4176
2023-05-12 2023-03-31 13F ALKERMES SHS G01767105 316,165 -25,356 -7.42 8,913 -0.12 4.2252
2023-02-14 2022-12-31 13F ALKERMES SHS G01767105 341,521 -160,629 -31.99 8,924 -20.42 4.8666
2022-11-14 2022-09-30 13F ALKERMES SHS G01767105 502,150 502,150 11,213 6.0073
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.