Who owns Insmed (INSM)
Which tracked institutional funds hold INSM, how they are positioned, and who is buying versus exiting — from SEC Form 13F-HR filings. See INSM company fundamentals →
Ownership as of the 2026-Q2 13F filings (latest filed 2026-09-22). 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
124 tracked funds added or opened INSM while 330 trimmed or exited it between 2026-Q1 and 2026-Q2 — 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
INSM’s largest tracked holder by dollar value, FMR LLC, sizes it at 0.1% of its own reported 13F book, while the median holder sizes it at 0.1% of theirs — a 0.0pp gap the other way — the median holder sizes INSM more heavily than its largest holder by dollar value does.
Book-share is each fund’s reported value in INSM 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 2026-Q1 and 2026-Q2, across 626 tracked filers holding INSM, 345 increased or opened the position and 379 reduced or closed it; over the same quarter, open-market insider Form 4s were net sales.
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 INSM between the 2026-Q1 and 2026-Q2 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 56
- Jupiter Topco LLC$278M
- MAVERICK CAPITAL LTD$229M
- Railway Pension Investments Ltd$64M
- Prosight Management, LP$40M
- Vestal Point Capital, LP$27M
- Caption Management, LLC$25M
Full exits 68
- Capital World Investors$223M
- NWI MANAGEMENT LP$166M
- Amundi$132M
- SUMMIT PARTNERS PUBLIC ASSET MANAGEMENT, LLC$107M
- GW&K Investment Management, LLC$102M
- JANUS HENDERSON GROUP PLC$69M
Largest adds
- Orbis Allan Gray Ltd$342M
- NORGES BANK$227M
- AMERIPRISE FINANCIAL INC$159M
- Qube Research & Technologies Ltd$155M
- Bellevue Group AG$147M
- BALYASNY ASSET MANAGEMENT L.P.$105M
Largest trims
- JPMORGAN CHASE & CO$2.6B
- Darwin Global Management, Ltd.$1.9B
- Invesco Ltd.$700M
- VANGUARD PORTFOLIO MANAGEMENT LLC$586M
- VANGUARD CAPITAL MANAGEMENT LLC$533M
- BlackRock, Inc.$488M
Institutional holders
One row per tracked fund, most shares held first (every row is from one quarter; reported value breaks ties). “% of value” is the fund’s share of this security’s tracked institutional value — not of shares outstanding.
| Fund | Shares | Reported value | % of value | Quarter |
|---|---|---|---|---|
| FMR LLC added | 16,143,583 | $1.7B | 8.0% | 2026-Q2 |
| BlackRock, Inc. added | 15,807,984 | $1.7B | 7.8% | 2026-Q2 |
| JPMORGAN CHASE & CO trimmed | 10,428,170 | $1.1B | 5.1% | 2026-Q2 |
| VANGUARD PORTFOLIO MANAGEMENT LLC added | 10,407,962 | $1.1B | 5.1% | 2026-Q2 |
| VANGUARD CAPITAL MANAGEMENT LLC added | 9,790,865 | $1.0B | 4.8% | 2026-Q2 |
| BAKER BROS. ADVISORS LP added | 8,796,111 | $938M | 4.3% | 2026-Q2 |
| Capital International Investors added | 8,238,124 | $878M | 4.1% | 2026-Q2 |
| Darwin Global Management, Ltd. trimmed | 6,431,163 | $674M | 3.1% | 2026-Q2 |
| AMERIPRISE FINANCIAL INC added | 6,179,571 | $659M | 3.0% | 2026-Q2 |
| Orbis Allan Gray Ltd added | 6,076,487 | $648M | 3.0% | 2026-Q2 |
| STATE STREET CORP added | 6,052,174 | $645M | 3.0% | 2026-Q2 |
| D. E. Shaw & Co., Inc. added | 5,877,959 | $627M | 2.9% | 2026-Q2 |
| Artisan Partners Limited Partnership trimmed | 5,441,718 | $580M | 2.7% | 2026-Q2 |
| RTW INVESTMENTS, LP | 4,842,880 | $516M | 2.4% | 2026-Q2 |
| GEODE CAPITAL MANAGEMENT, LLC trimmed | 4,220,155 | $449M | 2.1% | 2026-Q2 |
| PRICE T ROWE ASSOCIATES INC /MD/ added | 3,405,290 | $363M | 1.7% | 2026-Q2 |
| NORGES BANK added | 3,377,641 | $360M | 1.7% | 2026-Q2 |
| Jupiter Topco LLC new | 2,605,181 | $278M | 1.3% | 2026-Q2 |
| UBS Group AG added | 2,584,446 | $276M | 1.3% | 2026-Q2 |
| CITADEL ADVISORS LLC added | 2,556,973 | $273M | 1.3% | 2026-Q2 |
| FRANKLIN RESOURCES INC trimmed | 2,273,222 | $242M | 1.1% | 2026-Q2 |
| MAVERICK CAPITAL LTD added | 2,150,762 | $229M | 1.1% | 2026-Q2 |
| MILLENNIUM MANAGEMENT LLC added | 2,048,005 | $218M | 1.0% | 2026-Q2 |
| Qube Research & Technologies Ltd added | 1,682,334 | $179M | 0.8% | 2026-Q2 |
| WESTFIELD CAPITAL MANAGEMENT CO LP added | 1,629,561 | $174M | 0.8% | 2026-Q2 |
| Integral Health Asset Management, LLC added | 1,600,000 | $171M | 0.8% | 2026-Q2 |
| Duquesne Family Office LLC added | 1,424,690 | $152M | 0.7% | 2026-Q2 |
| GOLDMAN SACHS GROUP INC added | 1,409,885 | $150M | 0.7% | 2026-Q2 |
| VANGUARD FIDUCIARY TRUST CO added | 1,401,552 | $149M | 0.7% | 2026-Q2 |
| Bellevue Group AG added | 1,393,418 | $149M | 0.7% | 2026-Q2 |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC added | 1,335,071 | $142M | 0.7% | 2026-Q2 |
| BALYASNY ASSET MANAGEMENT L.P. added | 1,326,430 | $141M | 0.7% | 2026-Q2 |
| Paradigm Biocapital Advisors LP added | 1,325,977 | $141M | 0.7% | 2026-Q2 |
| NORTHERN TRUST CORP added | 1,315,325 | $140M | 0.6% | 2026-Q2 |
| Bank of New York Mellon Corp added | 1,312,756 | $140M | 0.6% | 2026-Q2 |
| TWO SIGMA INVESTMENTS, LP added | 1,242,222 | $132M | 0.6% | 2026-Q2 |
| MORGAN STANLEY trimmed | 1,233,498 | $132M | 0.6% | 2026-Q2 |
| Pictet Asset Management Holding SA added | 1,220,353 | $130M | 0.6% | 2026-Q2 |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC added | 1,213,963 | $129M | 0.6% | 2026-Q2 |
| Hood River Capital Management LLC added | 1,056,871 | $113M | 0.5% | 2026-Q2 |
| BANK OF AMERICA CORP /DE/ trimmed | 1,023,114 | $109M | 0.5% | 2026-Q2 |
| SEI INVESTMENTS CO trimmed | 1,015,870 | $108M | 0.5% | 2026-Q2 |
| Castle Hook Partners LP trimmed | 993,310 | $106M | 0.5% | 2026-Q2 |
| JENNISON ASSOCIATES LLC added | 905,094 | $97M | 0.4% | 2026-Q2 |
| Polar Capital Holdings Plc added | 890,872 | $95M | 0.4% | 2026-Q2 |
| FIL Ltd added | 856,214 | $91M | 0.4% | 2026-Q2 |
| PRINCIPAL FINANCIAL GROUP INC trimmed | 856,126 | $91M | 0.4% | 2026-Q2 |
| ADAGE CAPITAL PARTNERS GP, L.L.C. trimmed | 850,000 | $91M | 0.4% | 2026-Q2 |
| Fiera Capital Corp trimmed | 843,042 | $90M | 0.4% | 2026-Q2 |
| Legal & General Group Plc added | 826,431 | $88M | 0.4% | 2026-Q2 |
| FRONTIER CAPITAL MANAGEMENT CO LLC added | 795,242 | $85M | 0.4% | 2026-Q2 |
| AMERICAN CENTURY COMPANIES INC trimmed | 759,735 | $81M | 0.4% | 2026-Q2 |
| SAMLYN CAPITAL, LLC added | 732,568 | $78M | 0.4% | 2026-Q2 |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP added | 729,354 | $78M | 0.4% | 2026-Q2 |
| TimesSquare Capital Management, LLC added | 728,096 | $78M | 0.4% | 2026-Q2 |
| Clearbridge Investments, LLC added | 715,922 | $76M | 0.4% | 2026-Q2 |
| Ensign Peak Advisors, Inc added | 702,951 | $75M | 0.3% | 2026-Q2 |
| DEUTSCHE BANK AG\ added | 690,590 | $74M | 0.3% | 2026-Q2 |
| RAYMOND JAMES FINANCIAL INC trimmed | 660,601 | $70M | 0.3% | 2026-Q2 |
| Affinity Asset Advisors, LLC added | 650,000 | $69M | 0.3% | 2026-Q2 |
| WILLIAM BLAIR INVESTMENT MANAGEMENT, LLC trimmed | 629,831 | $67M | 0.3% | 2026-Q2 |
| Squarepoint Ops LLC added | 616,464 | $66M | 0.3% | 2026-Q2 |
| AQR CAPITAL MANAGEMENT LLC trimmed | 612,832 | $65M | 0.3% | 2026-Q2 |
| Railway Pension Investments Ltd new | 604,700 | $64M | 0.3% | 2026-Q2 |
| Swiss National Bank trimmed | 593,512 | $63M | 0.3% | 2026-Q2 |
| Nuveen, LLC added | 591,844 | $63M | 0.3% | 2026-Q2 |
| Artia Global Partners LP trimmed | 589,052 | $63M | 0.3% | 2026-Q2 |
| EVENTIDE ASSET MANAGEMENT, LLC added | 583,665 | $62M | 0.3% | 2026-Q2 |
| Aberdeen Group plc added | 577,437 | $62M | 0.3% | 2026-Q2 |
| Davern Capital Partners, LP added | 559,824 | $60M | 0.3% | 2026-Q2 |
| Candriam S.C.A. added | 555,131 | $59M | 0.3% | 2026-Q2 |
| WELLINGTON MANAGEMENT GROUP LLP added | 543,893 | $58M | 0.3% | 2026-Q2 |
| Point72 Asset Management, L.P. added | 536,997 | $57M | 0.3% | 2026-Q2 |
| Long Focus Capital Management, LLC added | 528,000 | $56M | 0.3% | 2026-Q2 |
| MARSHALL WACE, LLP added | 501,930 | $54M | 0.2% | 2026-Q2 |
| BNP PARIBAS ASSET MANAGEMENT Holding S.A. added | 475,307 | $51M | 0.2% | 2026-Q2 |
| ALLIANCEBERNSTEIN L.P. trimmed | 462,796 | $76M | 0.4% | 2026-Q2 |
| Bridgewater Associates, LP added | 455,392 | $49M | 0.2% | 2026-Q2 |
| Sumitomo Mitsui Trust Group, Inc. trimmed | 437,713 | $47M | 0.2% | 2026-Q2 |
| ROYAL BANK OF CANADA trimmed | 416,487 | $44M | 0.2% | 2026-Q2 |
| VANGUARD ASSET MANAGEMENT, Ltd added | 416,108 | $44M | 0.2% | 2026-Q2 |
| Palo Alto Investors LP trimmed | 413,980 | $44M | 0.2% | 2026-Q2 |
| DIMENSIONAL FUND ADVISORS LP added | 408,388 | $44M | 0.2% | 2026-Q2 |
| BNP PARIBAS FINANCIAL MARKETS trimmed | 400,765 | $43M | 0.2% | 2026-Q2 |
| Eagle Health Investments LP added | 384,130 | $41M | 0.2% | 2026-Q2 |
| NEUBERGER BERMAN GROUP LLC added | 378,816 | $40M | 0.2% | 2026-Q2 |
| Prosight Management, LP new | 375,609 | $40M | 0.2% | 2026-Q2 |
| Invesco Ltd. trimmed | 368,261 | $39M | 0.2% | 2026-Q2 |
| GATEWAY INVESTMENT ADVISERS LLC | 365,000 | $39M | 0.2% | 2026-Q2 |
| Rock Springs Capital Management LP added | 362,150 | $39M | 0.2% | 2026-Q2 |
| ENVESTNET ASSET MANAGEMENT INC added | 336,997 | $36M | 0.2% | 2026-Q2 |
| VICTORY CAPITAL MANAGEMENT INC trimmed | 306,651 | $33M | 0.2% | 2026-Q2 |
| CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM added | 304,798 | $32M | 0.2% | 2026-Q2 |
| NEW YORK STATE COMMON RETIREMENT FUND added | 304,236 | $32M | 0.2% | 2026-Q2 |
| SCHRODER INVESTMENT MANAGEMENT GROUP added | 298,372 | $32M | 0.1% | 2026-Q2 |
| Mitsubishi UFJ Asset Management Co., Ltd. added | 289,594 | $31M | 0.1% | 2026-Q2 |
| Defilade Capital Management, L.P. added | 281,838 | $30M | 0.1% | 2026-Q2 |
| HSBC HOLDINGS PLC added | 279,961 | $30M | 0.1% | 2026-Q2 |
| RHUMBLINE ADVISERS added | 272,715 | $29M | 0.1% | 2026-Q2 |
| First Turn Management, LLC added | 263,851 | $28M | 0.1% | 2026-Q2 |
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.