Lantheus Holdings, Inc.
US ˙ NasdaqGM ˙ US5165441032

SecurityLNTH / Lantheus Holdings, Inc.
InstitutionBoston Partners
Latest Disclosed Ownership470,658 shares
Latest Disclosed Value $ 35,715,970
Boston Partners ownership in LNTH / Lantheus Holdings, Inc.

On May 11, 2026 - Boston Partners filed a 13F-HR form disclosing ownership of 470,658 shares of Lantheus Holdings, Inc. (US:LNTH) valued at $35,699,409 USD as of March 31, 2026. The entity filed a previous 13F-HR on November 13, 2025 disclosing 0 shares of Lantheus Holdings, Inc.. The current value of the position is $47,183,464 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)
2026-05-11 2026-03-31 13F LANTHEUS HLDGS COM 516544103 470,658 470,658 35,716 0.0160
2025-11-13 2025-09-30 13F LANTHEUS HLDGS COM 516544103 0 -576,362 -100.00 0 -100.00
2025-08-12 2025-06-30 13F/A-1 LANTHEUS HLDGS COM 516544103 576,362 134,781 30.52 46,432 7.41 0.0516
2025-08-07 2025-06-30 13F LANTHEUS HLDGS COM 516544103 576,362 134,781 46,432 0.0213
2025-05-13 2025-03-31 13F LANTHEUS HLDGS COM 516544103 441,581 40,784 10.18 43,228 19.41 0.0523
2025-02-11 2024-12-31 13F LANTHEUS HLDGS COM 516544103 400,797 146,268 57.47 36,201 29.16 0.0440
2024-11-12 2024-09-30 13F LANTHEUS HLDGS COM 516544103 254,529 -399,372 -61.08 28,027 -50.11 0.0331
2024-08-14 2024-06-30 13F LANTHEUS HLDGS COM 516544103 653,901 -27,380 -4.02 56,182 31.59 0.0698
2024-05-28 2024-03-31 13F/A-1 LANTHEUS HLDGS COM 516544103 681,281 119,156 21.20 42,696 24.32 0.0509
2024-05-13 2024-03-31 13F LANTHEUS HLDGS COM 516544103 681,281 119,156 42,696 0.0211
2024-02-07 2023-12-31 13F LANTHEUS HLDGS COM 516544103 562,125 49,195 9.59 34,344 -2.78 0.0455
2023-11-08 2023-09-30 13F LANTHEUS HLDGS COM 516544103 512,930 67,729 15.21 35,326 -4.33 0.0489
2023-08-10 2023-06-30 13F LANTHEUS HLDGS COM 516544103 445,201 110,067 32.84 36,924 33.29 0.0497
2023-05-09 2023-03-31 13F LANTHEUS HLDGS COM 516544103 335,134 335,134 27,703 0.0381
2023-02-08 2022-12-31 13F LANTHEUS HLDGS COM 516544103 0 -5,013 -100.00 0 -100.00
2022-11-09 2022-09-30 13F LANTHEUS HLDGS COM 516544103 5,013 -7,277 -59.21 353 -56.53 0.0005
2022-08-10 2022-06-30 13F LANTHEUS HLDGS COM 516544103 12,290 -51,165 -80.63 812 -76.87 0.0011
2022-05-10 2022-03-31 13F LANTHEUS HLDGS COM 516544103 63,455 -57,103 -47.37 3,510 0.78 0.0043
2022-02-04 2021-12-31 13F LANTHEUS HLDGS COM 516544103 120,558 56,577 88.43 3,483 111.99 0.0042
2021-11-05 2021-09-30 13F LANTHEUS HLDGS COM 516544103 63,981 -81,172 -55.92 1,643 -59.06 0.0021
2021-08-12 2021-06-30 13F LANTHEUS HLDGS COM 516544103 145,153 -52,953 -26.73 4,013 -5.22 0.0051
2021-05-10 2021-03-31 13F LANTHEUS HLDGS COM 516544103 198,106 64,399 48.16 4,234 134.70 0.0057
2021-02-10 2020-12-31 13F/A-1 LANTHEUS HLDGS COM 516544103 133,707 133,707 1,804 0.0028
2021-02-04 2020-12-31 13F LANTHEUS HLDGS COM 516544103 133,707 133,707 1,804 1,082.2928
2019-02-07 2018-12-31 13F LANTHEUS HLDGS COM 516544103 0 -56,300 -100.00 0 -100.00
2018-11-14 2018-09-30 13F LANTHEUS HLDGS COM 516544103 56,300 -300,490 -84.22 842 -83.78 0.0010
2018-08-03 2018-06-30 13F LANTHEUS HLDGS COM 516544103 356,790 237,090 198.07 5,191 172.78 0.0062
2018-05-04 2018-03-31 13F LANTHEUS HLDGS COM 516544103 119,700 119,700 1,903 0.0023
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.