Who owns Lantheus Holdings, Inc. (LNTH)
Which tracked institutional funds hold LNTH, how they are positioned, and who is buying versus exiting — from SEC Form 13F-HR filings. See LNTH company fundamentals →
Ownership as of the 2026-Q1 13F filings (latest filed 2026-05-18). 13F is disclosed up to 45 days after quarter-end, so the most recent quarter fills in over the following weeks.
How the tape is positioned
132 tracked funds added or opened LNTH while 64 trimmed or exited it between 2025-Q4 and 2026-Q1 — the tape is split. When large holders disagree on a name, the funds moving first are sometimes ahead of the story.
A prompt to read the filings, not a verdict. 13F is a quarter-end snapshot disclosed up to 45 days late; a fund adds or exits for mandate, benchmark, and timing reasons that have nothing to do with a view on the stock. This is a starting question, not a signal to trade.
Conviction spread
LNTH’s largest tracked holder by dollar value, BlackRock, Inc., sizes it at 0.0% of its own reported 13F book, while the median holder sizes it at 0.0% of theirs — a 0.0pp gap the other way — the median holder sizes LNTH more heavily than its largest holder by dollar value does.
Book-share is each fund’s reported value in LNTH divided by its whole reported 13F book, so it is comparable across funds of different sizes and is unaffected by stock splits. A higher share means a fund has committed more of its book to the name — a starting question about conviction, not a verdict or a signal to trade.
Institutional & insider positioning
Between 2025-Q4 and 2026-Q1, across 404 tracked filers holding LNTH, 211 increased or opened the position and 189 reduced or closed it; over the same quarter, there were no open-market insider Form 4s.
This fuses two public signals for the same quarter — how tracked institutions changed their positions and whether insiders bought or sold in the open market. It describes what was filed; it is a starting question, not a verdict or a signal to trade.
New buyers & exits
Funds opening or closing a position in LNTH between the 2025-Q4 and 2026-Q1 13F filings, and the largest changes among funds holding it in both. New buyers and exits are counted on fund presence (split-invariant); adds and trims are measured on reported value.
New buyers 22
- VANGUARD PORTFOLIO MANAGEMENT LLC$241M
- VANGUARD CAPITAL MANAGEMENT LLC$221M
- BROWN ADVISORY INC$52M
- Boston Partners$36M
- VANGUARD FIDUCIARY TRUST CO$35M
- Longaeva Partners L.P.$29M
Full exits 27
- VANGUARD GROUP INC$438M
- Carmignac Gestion$75M
- Freestone Grove Partners LP$40M
- Vestal Point Capital, LP$24M
- Edgestream Partners, L.P.$8M
- PUBLIC SECTOR PENSION INVESTMENT BOARD$6M
Largest adds
- AMERICAN CENTURY COMPANIES INC$84M
- FMR LLC$63M
- FARALLON CAPITAL MANAGEMENT LLC$62M
- WELLINGTON MANAGEMENT GROUP LLP$50M
- HEALTHCARE OF ONTARIO PENSION PLAN TRUST FUND$40M
- UBS Group AG$39M
Largest trims
- M&T Bank Corp$370M
- NORGES BANK$25M
- CITADEL ADVISORS LLC$21M
- AQR CAPITAL MANAGEMENT LLC$18M
- JANUS HENDERSON GROUP PLC$18M
- Pacer Advisors, Inc.$17M
Institutional holders
One row per tracked fund, largest reported value first. “% of value” is the fund’s share of this security’s tracked institutional value — not of shares outstanding. Rows marked stale are from an earlier filing than the security’s latest quarter — that fund is absent from the newest snapshot (position exited, or reported under a different name).
| Fund | Shares | Reported value | % of value | Quarter |
|---|---|---|---|---|
| BlackRock, Inc. trimmed | 7,158,423 | $543M | 9.0% | 2026-Q1 |
| FARALLON CAPITAL MANAGEMENT LLC added | 5,583,479 | $424M | 7.0% | 2026-Q1 |
| JANUS HENDERSON GROUP PLC trimmed | 4,774,841 | $362M | 6.0% | 2026-Q1 |
| FMR LLC added | 4,625,794 | $351M | 5.8% | 2026-Q1 |
| VANGUARD PORTFOLIO MANAGEMENT LLC new | 3,174,274 | $241M | 4.0% | 2026-Q1 |
| VANGUARD CAPITAL MANAGEMENT LLC new | 2,914,314 | $221M | 3.7% | 2026-Q1 |
| STATE STREET CORP added | 2,429,803 | $184M | 3.0% | 2026-Q1 |
| AMERICAN CENTURY COMPANIES INC added | 1,781,106 | $135M | 2.2% | 2026-Q1 |
| GEODE CAPITAL MANAGEMENT, LLC added | 1,765,952 | $134M | 2.2% | 2026-Q1 |
| MORGAN STANLEY trimmed | 1,646,463 | $125M | 2.1% | 2026-Q1 |
| REINHART PARTNERS, LLC. added | 1,564,878 | $119M | 2.0% | 2026-Q1 |
| DIMENSIONAL FUND ADVISORS LP trimmed | 1,379,570 | $105M | 1.7% | 2026-Q1 |
| Swedbank AB | 1,228,743 | $93M | 1.5% | 2026-Q1 |
| TD Asset Management Inc added | 1,133,518 | $86M | 1.4% | 2026-Q1 |
| Point72 Asset Management, L.P. trimmed | 974,210 | $74M | 1.2% | 2026-Q1 |
| PRICE T ROWE ASSOCIATES INC /MD/ added | 919,732 | $70M | 1.2% | 2026-Q1 |
| UBS Group AG added | 867,675 | $66M | 1.1% | 2026-Q1 |
| NOMURA ASSET MANAGEMENT INTERNATIONAL INC. trimmed | 840,417 | $64M | 1.1% | 2026-Q1 |
| DEERFIELD MANAGEMENT COMPANY, L.P. | 827,999 | $63M | 1.0% | 2026-Q1 |
| NORTHERN TRUST CORP added | 804,923 | $61M | 1.0% | 2026-Q1 |
| WELLINGTON MANAGEMENT GROUP LLP added | 759,259 | $58M | 1.0% | 2026-Q1 |
| MACKENZIE FINANCIAL CORP added | 714,561 | $54M | 0.9% | 2026-Q1 |
| JPMORGAN CHASE & CO added | 739,473 | $54M | 0.9% | 2026-Q1 |
| BROWN ADVISORY INC new | 687,607 | $52M | 0.9% | 2026-Q1 |
| NORGES BANK trimmed | 524,941 | $51M | 0.8% | 2026-Q1 |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC added | 657,413 | $50M | 0.8% | 2026-Q1 |
| Epoch Investment Partners, Inc. added | 649,751 | $49M | 0.8% | 2026-Q1 |
| Polaris Capital Management, LLC added | 617,000 | $47M | 0.8% | 2026-Q1 |
| MARSHALL WACE, LLP added | 611,747 | $46M | 0.8% | 2026-Q1 |
| HEALTHCARE OF ONTARIO PENSION PLAN TRUST FUND added | 598,857 | $45M | 0.8% | 2026-Q1 |
| JACOBS LEVY EQUITY MANAGEMENT, INC added | 577,645 | $44M | 0.7% | 2026-Q1 |
| GOLDMAN SACHS GROUP INC added | 555,577 | $42M | 0.7% | 2026-Q1 |
| BANK OF AMERICA CORP /DE/ trimmed | 531,646 | $40M | 0.7% | 2026-Q1 |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC trimmed | 486,498 | $37M | 0.6% | 2026-Q1 |
| Boston Partners trimmed | 470,658 | $36M | 0.6% | 2026-Q1 |
| Bank of New York Mellon Corp trimmed | 463,751 | $35M | 0.6% | 2026-Q1 |
| VANGUARD FIDUCIARY TRUST CO new | 458,977 | $35M | 0.6% | 2026-Q1 |
| Portolan Capital Management, LLC trimmed | 417,390 | $32M | 0.5% | 2026-Q1 |
| Summit Street Capital Management, LLC added | 415,474 | $32M | 0.5% | 2026-Q1 |
| WILLIAM BLAIR INVESTMENT MANAGEMENT, LLC trimmed | 399,551 | $30M | 0.5% | 2026-Q1 |
| Longaeva Partners L.P. new | 383,945 | $29M | 0.5% | 2026-Q1 |
| BRIGADE CAPITAL MANAGEMENT, LP added | 363,745 | $28M | 0.5% | 2026-Q1 |
| Private Capital Management, LLC trimmed | 357,644 | $27M | 0.4% | 2026-Q1 |
| ADAGE CAPITAL PARTNERS GP, L.L.C. added | 346,755 | $26M | 0.4% | 2026-Q1 |
| VOYA INVESTMENT MANAGEMENT LLC added | 336,987 | $26M | 0.4% | 2026-Q1 |
| Alyeska Investment Group, L.P. added | 305,549 | $23M | 0.4% | 2026-Q1 |
| BNP PARIBAS FINANCIAL MARKETS trimmed | 299,705 | $23M | 0.4% | 2026-Q1 |
| Invesco Ltd. trimmed | 295,482 | $22M | 0.4% | 2026-Q1 |
| SILVERCREST ASSET MANAGEMENT GROUP LLC trimmed | 292,806 | $22M | 0.4% | 2026-Q1 |
| CITADEL ADVISORS LLC trimmed | 284,544 | $22M | 0.4% | 2026-Q1 |
| AMERIPRISE FINANCIAL INC added | 269,945 | $20M | 0.3% | 2026-Q1 |
| VICTORY CAPITAL MANAGEMENT INC added | 269,496 | $20M | 0.3% | 2026-Q1 |
| MILLENNIUM MANAGEMENT LLC added | 255,237 | $19M | 0.3% | 2026-Q1 |
| Defilade Capital Management, L.P. new | 249,401 | $19M | 0.3% | 2026-Q1 |
| DEUTSCHE BANK AG\ added | 236,885 | $18M | 0.3% | 2026-Q1 |
| PRINCIPAL FINANCIAL GROUP INC trimmed | 225,716 | $17M | 0.3% | 2026-Q1 |
| FIL Ltd added | 216,669 | $16M | 0.3% | 2026-Q1 |
| ExodusPoint Capital Management, LP added | 216,322 | $16M | 0.3% | 2026-Q1 |
| RHUMBLINE ADVISERS trimmed | 194,563 | $15M | 0.2% | 2026-Q1 |
| HOTCHKIS & WILEY CAPITAL MANAGEMENT LLC trimmed | 186,197 | $14M | 0.2% | 2026-Q1 |
| THOMPSON SIEGEL & WALMSLEY LLC trimmed | 176,967 | $13M | 0.2% | 2026-Q1 |
| Retirement Systems of Alabama added | 174,000 | $13M | 0.2% | 2026-Q1 |
| Sarissa Capital Management LP trimmed | 166,919 | $13M | 0.2% | 2026-Q1 |
| CITIGROUP INC trimmed | 160,225 | $12M | 0.2% | 2026-Q1 |
| Nuveen, LLC trimmed | 146,601 | $11M | 0.2% | 2026-Q1 |
| LOOMIS SAYLES & CO L P trimmed | 139,787 | $11M | 0.2% | 2026-Q1 |
| FRED ALGER MANAGEMENT, LLC added | 136,254 | $10M | 0.2% | 2026-Q1 |
| Assenagon Asset Management S.A. added | 132,319 | $10M | 0.2% | 2026-Q1 |
| California Public Employees Retirement System added | 131,776 | $10M | 0.2% | 2026-Q1 |
| Russell Investments Group, Ltd. added | 131,544 | $10M | 0.2% | 2026-Q1 |
| Swiss National Bank trimmed | 131,154 | $10M | 0.2% | 2026-Q1 |
| STATE OF WISCONSIN INVESTMENT BOARD trimmed | 126,437 | $10M | 0.2% | 2026-Q1 |
| Integral Health Asset Management, LLC added | 125,000 | $9M | 0.2% | 2026-Q1 |
| ALLIANCEBERNSTEIN L.P. added | 134,311 | $9M | 0.1% | 2026-Q1 |
| WELLS FARGO & COMPANY/MN trimmed | 117,433 | $9M | 0.1% | 2026-Q1 |
| VANGUARD GROUP INC trimmed | 6,574,530 | $438M | 7.2% | 2025-Q4 stale |
| WESTFIELD CAPITAL MANAGEMENT CO LP trimmed | 1,495,072 | $122M | 2.0% | 2025-Q2 stale |
| Carmignac Gestion added | 1,122,000 | $75M | 1.2% | 2025-Q4 stale |
| MACQUARIE GROUP LTD trimmed | 1,039,477 | $53M | 0.9% | 2025-Q3 stale |
| Freestone Grove Partners LP added | 608,526 | $40M | 0.7% | 2025-Q4 stale |
| Hood River Capital Management LLC trimmed | 407,177 | $33M | 0.6% | 2025-Q2 stale |
| Nitorum Capital, L.P. added | 344,444 | $28M | 0.5% | 2025-Q2 stale |
| FRONTIER CAPITAL MANAGEMENT CO LLC added | 315,513 | $26M | 0.4% | 2025-Q2 stale |
| Vestal Point Capital, LP added | 360,000 | $24M | 0.4% | 2025-Q4 stale |
| GMT CAPITAL CORP trimmed | 236,900 | $23M | 0.4% | 2025-Q1 stale |
| MPM BIOIMPACT LLC trimmed | 232,387 | $23M | 0.4% | 2025-Q1 stale |
| Artisan Partners Limited Partnership trimmed | 403,994 | $21M | 0.3% | 2025-Q3 stale |
| Clearbridge Investments, LLC added | 222,085 | $18M | 0.3% | 2025-Q2 stale |
| TWINBEECH CAPITAL LP added | 158,952 | $16M | 0.3% | 2025-Q1 stale |
| EAGLE GLOBAL ADVISORS LLC added | 181,150 | $15M | 0.2% | 2025-Q2 stale |
| SHAPIRO CAPITAL MANAGEMENT LLC new | 176,510 | $14M | 0.2% | 2025-Q2 stale |
| Penn Capital Management Company, LLC added | 146,903 | $14M | 0.2% | 2025-Q1 stale |
| Resolute Capital Asset Partners LLC added | 136,900 | $13M | 0.2% | 2025-Q1 stale |
| Driehaus Capital Management LLC trimmed | 126,909 | $12M | 0.2% | 2025-Q1 stale |
| Galvin, Gaustad & Stein, LLC new | 145,352 | $12M | 0.2% | 2025-Q2 stale |
| JUPITER ASSET MANAGEMENT LTD added | 136,392 | $11M | 0.2% | 2025-Q2 stale |
| WCM INVESTMENT MANAGEMENT, LLC added | 135,891 | $11M | 0.2% | 2025-Q2 stale |
| Corebridge Financial, Inc. trimmed | 110,064 | $11M | 0.2% | 2025-Q1 stale |
| Capital World Investors | 194,931 | $10M | 0.2% | 2025-Q3 stale |
| Select Equity Group, L.P. added | 100,843 | $10M | 0.2% | 2025-Q1 stale |
Ownership over time
Tracked institutional holder count and total shares held by filing quarter (independent scales). The curated-era tail and any mid-ingest latest quarter are handled honestly — a partial quarter is not drawn as a collapse.
Reading this table
Funds hold the same stock for different reasons — an index fund “holds” almost everything, an active manager sizes a name to a mandate and a benchmark, and each fund entered at its own price and time. Because 13F is filed up to 45 days after quarter-end, every row is a backward-looking snapshot; a manager may have traded since. Share-class siblings (a company’s A and C shares) are rolled up to one line so a dual-class name is never double-counted. Compare like-for-like. A large holder is not an endorsement, and a fund exiting is not a warning — this is a starting question, not a verdict.
About 13F filings
A Form 13F is a quarterly disclosure that institutional investment managers with over $100 million in US-listed equities must file with the SEC. In plain English: it is a snapshot of the long stock positions a fund held at the end of a quarter. It covers long US-listed equities only — not short positions, options, cash, or private holdings — and the funds shown are the large sample we track, not the complete 13F universe.