Lantheus Holdings, Inc.
US ˙ NasdaqGM ˙ US5165441032

SecurityLNTH / Lantheus Holdings, Inc.
InstitutionSei Investments Co
Latest Disclosed Ownership18,096 shares
Latest Disclosed Value $ 1,204,441
Sei Investments Co reports 49.53% decrease in ownership of LNTH / Lantheus Holdings, Inc.

On February 13, 2026 - Sei Investments Co filed a 13F-HR form disclosing ownership of 18,096 shares of Lantheus Holdings, Inc. (US:LNTH) valued at $1,204,289 USD as of December 31, 2025. The entity filed a previous 13F-HR on November 13, 2025 disclosing 35,853 shares of Lantheus Holdings, Inc.. This represents a change in shares of -49.53% during the quarter. The current value of the position is $1,814,124 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)
2026-02-13 2025-12-31 13F LANTHEUS HLDGS COM 516544103 18,096 -17,757 -49.53 1,204 -34.53
2025-11-13 2025-09-30 13F LANTHEUS HLDGS COM 516544103 35,853 -58,030 -61.81 1,839 -76.07 0.0020
2025-08-14 2025-06-30 13F LANTHEUS HLDGS COM 516544103 93,883 -41,807 -30.81 7,686 -41.97 0.0089
2025-05-14 2025-03-31 13F/A-1 LANTHEUS HLDGS COM 516544103 135,690 -14,913 -9.90 13,244 -1.72 0.0170
2025-05-13 2025-03-31 13F LANTHEUS HLDGS COM 516544103 153,702 3,099 13,943 0.0152
2025-02-11 2024-12-31 13F LANTHEUS HLDGS COM 516544103 150,603 -22,103 -12.80 13,475 -28.92 0.0173
2024-11-12 2024-09-30 13F LANTHEUS HLDGS COM 516544103 172,706 21,575 14.28 18,957 56.26 0.0246
2024-08-13 2024-06-30 13F LANTHEUS HLDGS COM 516544103 151,131 7,846 5.48 12,132 36.04 0.0172
2024-05-07 2024-03-31 13F LANTHEUS HLDGS COM 516544103 143,285 -7,153 -4.75 8,918 -4.39 0.0131
2024-02-14 2023-12-31 13F LANTHEUS HLDGS COM 516544103 150,438 -48,538 -24.39 9,328 -32.54 0.0150
2023-11-14 2023-09-30 13F LANTHEUS HLDGS COM 516544103 198,976 -19,812 -9.06 13,826 -24.70 0.0248
2023-08-11 2023-06-30 13F LANTHEUS HLDGS COM 516544103 218,788 -28,942 -11.68 18,361 -10.22 0.0320
2023-05-12 2023-03-31 13F LANTHEUS HLDGS COM 516544103 247,730 38,189 18.23 20,453 91.53 0.0380
2023-02-10 2022-12-31 13F LANTHEUS HLDGS COM 516544103 209,541 31,771 17.87 10,678 -14.59 0.0237
2022-11-14 2022-09-30 13F LANTHEUS HLDGS COM 516544103 177,770 13,762 8.39 12,502 15.59 0.0279
2022-08-15 2022-06-30 13F LANTHEUS HLDGS COM 516544103 164,008 16,886 11.48 10,816 33.09 0.0234
2022-05-13 2022-03-31 13F LANTHEUS HLDGS COM 516544103 147,122 -89,886 -37.93 8,127 18.66 0.0163
2022-02-14 2021-12-31 13F LANTHEUS HLDGS COM 516544103 237,008 206,259 670.78 6,849 764.77 0.0128
2021-11-12 2021-09-30 13F LANTHEUS HLDGS COM 516544103 30,749 -1,466 -4.55 792 -11.31 0.0017
2021-08-06 2021-06-30 13F LANTHEUS HLDGS COM 516544103 32,215 32,215 893 0.0020
2019-08-14 2019-06-30 13F LANTHEUS HLDGS COM 516544103 0 -2,558 -100.00 0 -100.00
2019-05-15 2019-03-31 13F LANTHEUS HLDGS COM 516544103 2,558 -163 -5.99 63 53.66 0.0002
2019-02-13 2018-12-31 13F LANTHEUS HLDGS COM 516544103 2,721 0 0.00 41 0.00 0.0001
2018-11-08 2018-09-30 13F LANTHEUS HLDGS COM 516544103 2,721 161 6.29 41 10.81 0.0001
2018-08-03 2018-06-30 13F LANTHEUS HLDGS COM 516544103 2,560 2,245 712.70 37 640.00 0.0001
2018-05-11 2018-03-31 13F LANTHEUS HLDGS COM 516544103 315 -8,943 -96.60 5 -97.35 0.0000
2018-02-08 2017-12-31 13F LANTHEUS HLDGS COM 516544103 9,258 1,429 18.25 189 35.97 0.0007
2017-11-06 2017-09-30 13F LANTHEUS HLDGS COM 516544103 7,829 5,126 189.64 139 189.58 0.0005
2017-07-31 2017-06-30 13F LANTHEUS HLDGS COM 516544103 2,703 996 58.35 48 128.57 0.0002
2017-05-05 2017-03-31 13F LANTHEUS HLDGS COM 516544103 1,707 422 32.84 21 90.91 0.0001
2017-02-02 2016-12-31 13F LANTHEUS HLDGS COM 516544103 1,285 1,285 11 0.0001
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.