Alkermes plc
US ˙ NasdaqGS ˙ IE00B56GVS15

SecurityALKS / Alkermes plc
InstitutionCitigroup Inc
Latest Disclosed Ownership47,450 shares
Latest Disclosed Value $ 1,677,832
Citigroup Inc ownership in ALKS / Alkermes plc

On May 11, 2026 - Citigroup Inc filed a 13F-HR form disclosing ownership of 47,450 shares of Alkermes plc (US:ALKS) valued at $1,677,832 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 73,374 shares of Alkermes plc. This represents a change in shares of -35.33% during the quarter. The current value of the position is $2,028,962 USD.

Citigroup Inc has a history of taking positions in derivatives of the underlying security (ALKS) in the form of stock options. The firm currently holds call options representing 0 of underlying shares valued at $0 USD and put options representing 0 of underlying shares valued at $0 USD .

Note: prior versions of this page mistakenly stated that the share values represented the number of options, not the number of underlying shares. For more information on the data backing these reports, please see the SEC document Frequently Asked Questions About Form 13F.

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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Institutional Put/Call Ratios
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In addition to reporting standard equity and debt issues, institutions with more than 100MM assets under management must also disclose their put and call option holdings. Since put options generally indicate negative sentiment, and call options indicate positive sentiment, we can get a sense of the overall institutional sentiment by plotting the ratio of puts to calls. The chart to the right plots the historical put/call ratio for this instrument.

Using Put/Call Ratio as an indicator of investor sentiment overcomes one of the key deficiencies of using total institutional ownership, which is that a significant amount of assets under management are invested passively to track indices. Passively-managed funds do not typically buy options, so the put/call ratio indicator more closely tracks the sentiment of actively-managed funds.

ALKS / Alkermes plc Historical Put/Call Ratio
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)
2026-05-11 2026-03-31 13F ALKERMES SHS G01767105 47,450 -25,924 -35.33 1,678 -18.31 0.0004
2026-02-13 2025-12-31 13F ALKERMES SHS G01767105 73,374 7,473 11.34 2,053 3.84 0.0009
2025-11-10 2025-09-30 13F ALKERMES SHS G01767105 65,901 -121,945 -64.92 1,977 -63.21 0.0009
2025-08-11 2025-06-30 13F ALKERMES SHS G01767105 187,846 -174,539 -48.16 5,374 -55.09 0.0026
2025-05-12 2025-03-31 13F ALKERMES SHS G01767105 362,385 30,717 9.26 11,966 25.45 0.0061
2025-02-12 2024-12-31 13F ALKERMES SHS G01767105 331,668 106,810 47.50 9,539 51.57 0.0057
2024-11-12 2024-09-30 13F ALKERMES SHS G01767105 224,858 65,536 41.13 6,294 63.92 0.0036
2024-08-12 2024-06-30 13F ALKERMES SHS G01767105 159,322 -246,083 -60.70 3,840 -65.02 0.0025
2024-05-10 2024-03-31 13F ALKERMES SHS G01767105 405,405 150,729 59.18 10,974 55.35 0.0072
2024-02-09 2023-12-31 13F ALKERMES SHS G01767105 254,676 62,020 32.19 7,065 30.91 0.0050
2023-12-06 2023-09-30 13F/A-1 ALKERMES SHS G01767105 192,656 19,911 11.53 5,396 -0.18 0.0040
2023-11-09 2023-09-30 13F ALKERMES SHS G01767105 192,656 19,911 5,396 0.0016
2023-08-10 2023-06-30 13F ALKERMES SHS G01767105 172,745 -52,781 -23.40 5,407 -14.96 0.0035
2023-05-11 2023-03-31 13F ALKERMES SHS G01767105 225,526 62,056 37.96 6,358 48.84 0.0045
2023-02-09 2022-12-31 13F ALKERMES SHS G01767105 163,470 -135,895 -45.39 4,271 -36.10 0.0034
2022-11-10 2022-09-30 13F ALKERMES SHS G01767105 299,365 -10,512 -3.39 6,684 -27.59 0.0048
2022-08-10 2022-06-30 13F ALKERMES SHS G01767105 309,877 192,915 164.94 9,231 199.90 0.0069
2022-05-12 2022-03-31 13F ALKERMES SHS G01767105 116,962 -128,093 -52.27 3,078 -46.00 0.0019
2022-02-10 2021-12-31 13F ALKERMES SHS G01767105 245,055 62,634 34.33 5,700 1.32 0.0031
2021-11-10 2021-09-30 13F ALKERMES SHS G01767105 182,421 -24,141 -11.69 5,626 11.08 0.0033
2021-08-10 2021-06-30 13F ALKERMES SHS G01767105 206,562 -2,304,100 -91.77 5,065 -89.20 0.0030
2021-05-13 2021-03-31 13F ALKERMES SHS G01767105 2,510,662 -834,501 -24.95 46,899 -29.73 0.0303
2021-02-11 2020-12-31 13F ALKERMES SHS G01767105 3,345,163 -1,337,305 -28.56 66,737 -13.99 0.0394
2020-11-12 2020-09-30 13F ALKERMES SHS G01767105 4,682,468 -361,454 -7.17 77,588 -20.73 0.0506
2020-08-12 2020-06-30 13F ALKERMES SHS G01767105 5,043,922 320,664 6.79 97,877 43.71 0.0764
2020-05-12 2020-03-31 13F ALKERMES SHS G01767105 4,723,258 4,616,010 4,304.05 68,109 3,014.27 0.0616
2020-02-12 2019-12-31 13F ALKERMES SHS G01767105 107,248 -63,919 -37.34 2,187 -34.50 0.0016
2019-11-08 2019-09-30 13F ALKERMES SHS G01767105 171,167 -113,429 -39.86 3,339 -47.94 0.0026
2019-08-12 2019-06-30 13F ALKERMES SHS G01767105 284,596 267,149 1,531.20 6,414 908.49 0.0052
2019-05-13 2019-03-31 13F ALKERMES SHS G01767105 17,447 -125,552 -87.80 636 -84.93 0.0006
2019-02-12 2018-12-31 13F ALKERMES SHS G01767105 142,999 94,472 194.68 4,220 104.95 0.0043
2018-11-13 2018-09-30 13F ALKERMES SHS G01767105 48,527 20,305 71.95 2,059 77.35 0.0018
2018-08-10 2018-06-30 13F ALKERMES SHS G01767105 28,222 -22,940 -44.84 1,161 -60.86 0.0011
2018-05-11 2018-03-31 13F ALKERMES SHS G01767105 51,162 -29,809 -36.81 2,966 -33.08 0.0024
2018-02-12 2017-12-31 13F ALKERMES SHS G01767105 80,971 13,905 20.73 4,432 29.97 0.0036
2017-11-13 2017-09-30 13F ALKERMES SHS G01767105 67,066 4,274 6.81 3,410 -6.32 0.0028
2017-08-11 2017-06-30 13F ALKERMES SHS G01767105 62,792 21,437 51.84 3,640 50.41 0.0033
2017-05-12 2017-03-31 13F ALKERMES SHS G01767105 41,355 -105,496 -71.84 2,420 -70.35 0.0022
2017-02-10 2016-12-31 13F ALKERMES SHS G01767105 146,851 109,968 298.15 8,162 370.43 0.0074
2016-11-10 2016-09-30 13F ALKERMES SHS G01767105 36,883 19,054 106.87 1,735 125.03 0.0016
2016-08-12 2016-06-30 13F ALKERMES SHS G01767105 17,829 -14,688 -45.17 771 -30.67 0.0008
2016-05-13 2016-03-31 13F ALKERMES SHS G01767105 32,517 5,722 21.35 1,112 -47.74 0.0012
2016-02-12 2015-12-31 13F ALKERMES SHS G01767105 26,795 -50,641 -65.40 2,128 -53.16 0.0021
2015-11-13 2015-09-30 13F ALKERMES SHS G01767105 77,436 1,979 2.62 4,543 -6.43 0.0043
2015-08-13 2015-06-30 13F ALKERMES SHS G01767105 75,457 1,080 1.45 4,855 7.06 0.0043
2015-05-14 2015-03-31 13F ALKERMES SHS G01767105 74,377 24,202 48.24 4,535 54.36 0.0044
2015-02-17 2014-12-31 13F ALKERMES SHS G01767105 50,175 -26,046 -34.17 2,938 -10.10 0.0026
2014-11-14 2014-09-30 13F ALKERMES SHS G01767105 76,221 41,360 118.64 3,268 86.21 0.0029
2014-08-14 2014-06-30 13F ALKERMES SHS G01767105 34,861 -8,851 -20.25 1,755 -8.93 0.0017
2014-05-15 2014-03-31 13F ALKERMES SHS G01767105 43,712 36,056 470.95 1,927 519.61 0.0020
2014-02-14 2013-12-31 13F ALKERMES SHS G01767105 7,656 -23,707 -75.59 311 -70.49 0.0003
2013-11-14 2013-09-30 13F ALKERMES SHS G01767105 31,363 26,663 567.30 1,054 686.57 0.0010
2013-08-14 2013-06-30 13F ALKERMES SHS G01767105 4,700 4,700 134 0.0001
Disclosed Call Options
File
Date
Effective
Date
Form Security Class ID Opt Avg Share
Price
Shares ΔShares
(%)
Value
(x1000)
ΔValue
(%)
Prior Allocation
(%)
Allocation
(%)
ΔAllocation
(%)
Cost Basis
(x1000)
Profit
(x1000)
Return
(%)
2025-05-12 2025-03-31 13F ALKERMES SHS Call 0 -100.00 0 -100.00 n/a n/a n/a
2025-02-12 2024-12-31 13F ALKERMES SHS Call 21,000 604 n/a n/a n/a
2023-12-06 2023-09-30 13F/A ALKERMES SHS Call 0 -100.00 0 -100.00 n/a n/a n/a
2023-11-09 2023-09-30 13F ALKERMES SHS Call 0 0 n/a n/a n/a
2023-08-10 2023-06-30 13F ALKERMES SHS Call 15,000 0.00 470 11.14 n/a n/a n/a
2023-05-11 2023-03-31 13F ALKERMES SHS Call 15,000 -40.00 423 -35.38 n/a n/a n/a
2023-02-09 2022-12-31 13F ALKERMES SHS Call 25,000 653 n/a n/a n/a
2022-08-10 2022-06-30 13F ALKERMES SHS Call 0 -100.00 0 -100.00 n/a n/a n/a
2022-05-12 2022-03-31 13F ALKERMES SHS Call 134,900 3,549 n/a n/a n/a
2021-05-13 2021-03-31 13F ALKERMES SHS Call 0 -100.00 0 -100.00 n/a n/a n/a
2021-02-11 2020-12-31 13F ALKERMES SHS Call 37,700 1,994.44 752 2,406.67 n/a n/a n/a
2020-11-12 2020-09-30 13F ALKERMES SHS Call 1,800 -90.58 30 -91.91 n/a n/a n/a
2020-08-12 2020-06-30 13F ALKERMES SHS Call 19,100 189.39 371 290.53 n/a n/a n/a
2020-05-12 2020-03-31 13F ALKERMES SHS Call 6,600 -33.33 95 -52.97 n/a n/a n/a
2020-02-12 2019-12-31 13F ALKERMES SHS Call 9,900 -40.00 202 -37.27 n/a n/a n/a
2019-11-08 2019-09-30 13F ALKERMES SHS Call 16,500 -14.51 322 -25.98 n/a n/a n/a
2019-08-12 2019-06-30 13F ALKERMES SHS Call 19,300 -63.58 435 -77.51 n/a n/a n/a
2019-05-13 2019-03-31 13F ALKERMES SHS Call 53,000 55.88 1,934 92.82 n/a n/a n/a
2019-02-12 2018-12-31 13F ALKERMES SHS Call 34,000 39.92 1,003 -2.72 n/a n/a n/a
2018-11-13 2018-09-30 13F ALKERMES SHS Call 24,300 -17.63 1,031 -15.07 n/a n/a n/a
2018-08-10 2018-06-30 13F ALKERMES SHS Call 29,500 -3.91 1,214 -31.76 n/a n/a n/a
2018-05-11 2018-03-31 13F ALKERMES SHS Call 30,700 -25.30 1,779 -20.90 n/a n/a n/a
2018-02-12 2017-12-31 13F ALKERMES SHS Call 41,100 13.85 2,249 22.56 n/a n/a n/a
2017-11-13 2017-09-30 13F ALKERMES SHS Call 36,100 159.71 1,835 127.67 n/a n/a n/a
2017-08-11 2017-06-30 13F ALKERMES SHS Call 13,900 -37.95 806 -38.47 n/a n/a n/a
2017-05-12 2017-03-31 13F ALKERMES SHS Call 22,400 169.88 1,310 184.16 n/a n/a n/a
2017-02-10 2016-12-31 13F ALKERMES SHS Call 8,300 88.64 461 122.71 n/a n/a n/a
2016-11-10 2016-09-30 13F ALKERMES SHS Call 4,400 12.82 207 22.49 n/a n/a n/a
2016-08-12 2016-06-30 13F ALKERMES SHS Call 3,900 -70.90 169 -63.10 n/a n/a n/a
2016-05-13 2016-03-31 13F ALKERMES SHS Call 13,400 306.06 458 74.81 n/a n/a n/a
2016-02-12 2015-12-31 13F ALKERMES SHS Call 3,300 -15.38 262 14.41 n/a n/a n/a
2015-11-13 2015-09-30 13F ALKERMES SHS Call 3,900 160.00 229 136.08 n/a n/a n/a
2015-08-13 2015-06-30 13F ALKERMES SHS Call 1,500 97 n/a n/a n/a
2014-11-14 2014-09-30 13F ALKERMES SHS Call 0 -100.00 0 -100.00 n/a n/a n/a
2014-08-14 2014-06-30 13F ALKERMES SHS Call 58,400 2,939 n/a n/a n/a
Disclosed Put Options
File
Date
Effective
Date
Form Security Class ID Opt Avg Share Price Shares ΔShares
(%)
Value
(x1000)
ΔValue
(%)
Prior Allocation
(%)
Allocation
(%)
ΔAllocation
(%)
Cost Basis
(x1000)
Profit
(x1000)
Return
(%)
2025-05-12 2025-03-31 13F ALKERMES SHS Put 0 -100.00 0 -100.00 n/a n/a n/a
2025-02-12 2024-12-31 13F ALKERMES SHS Put 21,000 604 n/a n/a n/a
2023-12-06 2023-09-30 13F/A ALKERMES SHS Put 0 -100.00 0 -100.00 n/a n/a n/a
2023-11-09 2023-09-30 13F ALKERMES SHS Put 0 0 n/a n/a n/a
2023-08-10 2023-06-30 13F ALKERMES SHS Put 15,000 0.00 470 11.14 n/a n/a n/a
2023-05-11 2023-03-31 13F ALKERMES SHS Put 15,000 -40.00 423 -35.38 n/a n/a n/a
2023-02-09 2022-12-31 13F ALKERMES SHS Put 25,000 653 n/a n/a n/a
2021-05-13 2021-03-31 13F ALKERMES SHS Put 0 -100.00 0 -100.00 n/a n/a n/a
2021-02-11 2020-12-31 13F ALKERMES SHS Put 35,400 13.46 706 36.56 n/a n/a n/a
2020-11-12 2020-09-30 13F ALKERMES SHS Put 31,200 -13.09 517 -25.82 n/a n/a n/a
2020-08-12 2020-06-30 13F ALKERMES SHS Put 35,900 124.38 697 201.73 n/a n/a n/a
2020-05-12 2020-03-31 13F ALKERMES SHS Put 16,000 52.38 231 7.94 n/a n/a n/a
2020-02-12 2019-12-31 13F ALKERMES SHS Put 10,500 -5.41 214 -1.38 n/a n/a n/a
2019-11-08 2019-09-30 13F ALKERMES SHS Put 11,100 -48.61 217 -55.44 n/a n/a n/a
2019-08-12 2019-06-30 13F ALKERMES SHS Put 21,600 -41.46 487 -63.82 n/a n/a n/a
2019-05-13 2019-03-31 13F ALKERMES SHS Put 36,900 113.29 1,346 163.41 n/a n/a n/a
2019-02-12 2018-12-31 13F ALKERMES SHS Put 17,300 188.33 511 100.39 n/a n/a n/a
2018-11-13 2018-09-30 13F ALKERMES SHS Put 6,000 -79.45 255 -78.79 n/a n/a n/a
2018-08-10 2018-06-30 13F ALKERMES SHS Put 29,200 167.89 1,202 90.19 n/a n/a n/a
2018-05-11 2018-03-31 13F ALKERMES SHS Put 10,900 -47.85 632 -44.76 n/a n/a n/a
2018-02-12 2017-12-31 13F ALKERMES SHS Put 20,900 533.33 1,144 580.95 n/a n/a n/a
2017-11-13 2017-09-30 13F ALKERMES SHS Put 3,300 -37.74 168 -45.28 n/a n/a n/a
2017-08-11 2017-06-30 13F ALKERMES SHS Put 5,300 -14.52 307 -15.43 n/a n/a n/a
2017-05-12 2017-03-31 13F ALKERMES SHS Put 6,200 -37.37 363 -34.00 n/a n/a n/a
2017-02-10 2016-12-31 13F ALKERMES SHS Put 9,900 -23.85 550 -9.98 n/a n/a n/a
2016-11-10 2016-09-30 13F ALKERMES SHS Put 13,000 381.48 611 422.22 n/a n/a n/a
2016-08-12 2016-06-30 13F ALKERMES SHS Put 2,700 -89.69 117 -86.94 n/a n/a n/a
2016-05-13 2016-03-31 13F ALKERMES SHS Put 26,200 322.58 896 82.11 n/a n/a n/a
2016-02-12 2015-12-31 13F ALKERMES SHS Put 6,200 5.08 492 42.20 n/a n/a n/a
2015-11-13 2015-09-30 13F ALKERMES SHS Put 5,900 47.50 346 34.63 n/a n/a n/a
2015-08-13 2015-06-30 13F ALKERMES SHS Put 4,000 257 n/a n/a n/a
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.