Ranked by reported Q1 2026 13F market value
Share of total reported institutional value in INSM held by the largest 10 / 25 filers.
| # | Institution | Shares Held | Market Value | QoQ Change | Ownership % | % of Fund |
|---|---|---|---|---|---|---|
| 1 | BlackRock, Inc. | 16.7M | $2.73B | +10.7% | 7.695% | 0.05% |
| 2 | Darwin Global Management, Ltd. | 16.8M | $2.58B | -19.7% | 7.753% | 68.33% |
| 3 | FMR LLC | 13.2M | $2.15B | +32.6% | 6.071% | 0.12% |
| 4 | VANGUARD PORTFOLIO MANAGEMENT LLC | 10.4M | $1.70B | — | 4.785% | 0.09% |
| 5 | VANGUARD CAPITAL MANAGEMENT LLC | 9.6M | $1.58B | — | 4.448% | 0.04% |
| 6 | BAKER BROS. ADVISORS LP | 7.4M | $1.21B | +12.6% | 3.424% | 6.97% |
| 7 | Artisan Partners Limited Partnership | 6.5M | $1.07B | +34.8% | 3.011% | 1.73% |
| 8 | D. E. Shaw & Co., Inc. | 5.6M | $922.7M | +29.3% | 2.603% | 0.87% |
| 9 | Capital International Investors | 5.6M | $914.9M | +8.6% | 2.581% | 0.21% |
| 10 | STATE STREET CORP | 5.6M | $907.8M | +6.7% | 2.561% | 0.03% |
| 11 | RTW INVESTMENTS, LP | 4.8M | $791.9M | 0.0% | 2.234% | 7.88% |
| 12 | GEODE CAPITAL MANAGEMENT, LLC | 4.5M | $733.3M | +3.5% | 2.053% | 0.05% |
| 13 | AMERIPRISE FINANCIAL INC | 3.1M | $500.0M | +55.3% | 1.411% | 0.12% |
| 14 | FRANKLIN RESOURCES INC | 2.6M | $428.0M | -5.0% | 1.208% | 0.10% |
| 15 | CITADEL ADVISORS LLC | 2.6M | $427.3M | +44.5% | 1.206% | 0.20% |
| 16 | Invesco Ltd. | 2.0M | $325.2M | -27.1% | 0.918% | 0.05% |
| 17 | Orbis Allan Gray Ltd | 1.9M | $306.2M | -55.2% | 0.864% | 1.29% |
| 18 | UBS Group AG | 1.7M | $284.1M | -10.9% | 0.802% | 0.04% |
| 19 | BANK OF AMERICA CORP /DE/ | 1.5M | $245.7M | -13.0% | 0.693% | 0.02% |
| 20 | Integral Health Asset Management, LLC | 1.5M | $245.3M | +20.0% | 0.692% | 15.16% |
| 21 | WESTFIELD CAPITAL MANAGEMENT CO LP | 1.5M | $240.1M | +239.5% | 0.677% | 1.01% |
| 22 | SEI INVESTMENTS CO | 1.4M | $228.2M | +56.8% | 0.644% | 0.21% |
| 23 | Capital World Investors | 1.4M | $222.7M | — | 0.628% | 0.03% |
| 24 | VANGUARD FIDUCIARY TRUST CO | 1.4M | $221.5M | — | 0.625% | 0.06% |
| 25 | MORGAN STANLEY | 1.3M | $217.7M | -18.4% | 0.614% | 0.01% |
denotes a marquee investor (Buffett, Burry, ARK, Tiger Global, Pershing Square, Baupost and other widely-followed managers). “% of Fund” shows how much of that investor’s total 13F portfolio is invested in INSM — a direct measure of their conviction.
Filings activity in INSM during Q1 2026, grouped by how each filer changed its position.
8 quarters of 13F filings · Δ columns show change vs prior quarter
| Quarter | Inst. Holders | Δ Holders | Ownership % | Δ Ownership | Total 13F Value | Δ Value |
|---|---|---|---|---|---|---|
| Q1 2026 | 656 | 0.5% | 143.48% | 27.10 pp | $30.43B | 16% |
| Q4 2025 | 659 | +21% | 170.58% | +33.75 pp | $36.18B | +25% |
| Q3 2025 | 546 | +8.8% | 136.83% | +45.31 pp | $29.02B | +50% |
| Q2 2025 | 502 | +16% | 91.52% | +27.90 pp | $19.41B | +44% |
| Q1 2025 | 432 | +3.1% | 63.62% | +7.89 pp | $13.49B | +14% |
| Q4 2024 | 419 | +5.0% | 55.73% | 1.54 pp | $11.82B | 2.7% |
| Q3 2024 | 399 | +9.6% | 57.27% | +8.02 pp | $12.15B | +16% |
| Q2 2024 | 364 | — | 49.25% | — | $10.44B | — |
Source: SEC 13F institutional filings. Ownership % requires market cap data and will show once linked. Δ columns compare to the immediately prior filed quarter.
Quick answers to the most common questions about buying INSM stock.
Based on Q1 2026 13F filings, institutional ownership of Insmed Incorporated stands at 143.5%, held across 656 reporting institutions.
BlackRock, Inc. is the largest reported institutional holder of INSM, with approximately 16,678,146 shares worth $2.73B as of Q1 2026.
Yes — 1 widely-followed marquee investor appear among the top 25 institutional holders of INSM, including CITADEL ADVISORS LLC.
Our composite Smart Money Score for INSM is 35 out of 100 (Bearish). It combines net institutional buying activity, ownership shift, marquee investor presence, and holder-count growth.
105 institutions opened new positions in INSM during Q1 2026, while 108 fully exited. 217 added to existing positions and 333 trimmed.
INSM institutional ownership fell by 27.10 percentage points quarter-over-quarter, with a net change of -3 holders.
The top 10 institutions account for 51.8% of all reported 13F value in INSM, and the top 25 account for 69.6%.
All data is sourced from SEC Form 13F filings, which institutional investment managers with at least $100M in assets are required to file each quarter. We process every 13F filing from EDGAR and recompute the aggregates after each cycle. Insider transactions are sourced from Form 4 filings.
Insmed Incorporated (INSM) Institutional Ownership