Comparable stake leader
FMR LLC
SEC ownership of INSMED Inc
Top holders, 13D/G large-stake signals, insider positions, and transaction flow tied to CIK 0001104506.
Disclosed value leader
BlackRock, Inc.
Comparable rows
50/50
Latest evidence
17 Aug 2026
- Public ticker
- INSM on Nasdaq
- Parsed ownership sources
-
13D/G, 13F, and 3/4/5
Source: Parsed SEC ownership filingsUse: Compare filing families carefully
- Largest SEC-reported holder
-
FMR LLC
Ranking: Comparable ownership first, then disclosed value
- Comparable ownership rows
-
50 of 50
Meaning: Rows with safely comparable ownership %
- Latest 13D/G holder
-
FMR LLC
Source: Latest parsed Schedule 13D/G stake
- Latest parsed ownership date
-
17 Aug 2026
Freshness: Most recent filing date in this holder set
- Issuer CIK
- 0001104506
- Issuer location
- Bridgewater, NJ
Ownership snapshot
CIK-linked ownership evidence from parsed SEC filings.
3 signals
Issuer
Names, identifiers, and filing context for this profile.
2 identity fields
Ownership snapshot
Top shareholders of INSMED Inc (13F + 13D/G + 3/4/5)
Grouped by holder across the latest SEC ownership disclosures. Start with comparable ownership when available, then verify the linked 13F, 13D/G, or 3/4/5 evidence.
Comparable stake leader
FMR LLC
Disclosed value leader
BlackRock, Inc.
Comparable rows
50/50
Latest evidence
17 Aug 2026
13D/G
13F
3/4/5
Lead comparable stake: 7.4%
13D/G row: FMR LLC
Showing 1-8 of 50 holder rows.
Quick read
FMR LLC leads the comparable SEC ownership view at 7.4%.
50 of 50 rows have a safely comparable ownership percentage. Use this as a filing-backed starting point, then open the detailed table for source links, reporting role, position value, share count, and filing date.
Open SEC evidence
Opens FMR LLC's linked filing trail.
Comparable ownership
Top 5
FMR LLC
7.4%
BlackRock, Inc.
6.6%
VANGUARD CAPITAL MANAGEMENT LLC
5.3%
JPMORGAN CHASE & CO
4.7%
PRICE T ROWE ASSOCIATES INC /MD/
3.3%
Ownership % is shown only when SEC disclosures are safely comparable across share classes.
Detailed SEC evidence table Showing 1-8 of 50 holder rows
| Holder | Evidence | Ownership % | Position | 12M Net Δ | As of |
|---|---|---|---|---|---|
| FMR LLC |
13D/G
13F
Company
|
7.4%
|
$1,864,509,880
16,127,583 shares
|
+$344,797,229 | 30 Jun 2026 |
| BlackRock, Inc. |
13D/G
13F
Company
|
6.6%
|
$2,457,696,288
14,121,445 shares
|
+$764,349,568 | 31 Dec 2025 |
| VANGUARD CAPITAL MANAGEMENT LLC |
13D/G
13F
Vanguard Capital Management · Company
|
5.3%
|
$1,882,915,303
11,514,893 shares
|
$0 | 31 Mar 2026 |
| JPMORGAN CHASE & CO |
13D/G
13F
Company
|
4.7%
|
$1,105,183,654
10,365,622 shares
|
-$1,348,633,593 | 30 Jun 2026 |
| PRICE T ROWE ASSOCIATES INC /MD/ |
13D/G
13F
T. Rowe Price Associates, Inc. · Company
|
3.3%
|
$998,278,616
6,932,009 shares
|
-$619,088,189 | 30 Sep 2025 |
| Darwin Global Management, Ltd. |
13D/G
13F
Company
|
3%
|
$743,506,754
6,431,163 shares
|
-$1,199,340,568 | 30 Jun 2026 |
| William Lewis |
3/4/5
Chair and CEO, Director
|
0.34%
|
$94,403,772
726,906 shares
mixed-class rows
|
-$32,791,057 | 23 Jul 2026 |
| Melvin Sharoky MD |
3/4/5
Director
|
0.12%
|
$28,563,602
267,901 shares
|
-$6,191,750 | 17 Aug 2026 |
How to read this table
Rows are grouped by holder and ranked first by SEC-reported ownership % when it is safely comparable, then by disclosed holdings value. — indicates unavailable or non-comparable values; "mixed-class rows" means the latest filing spans non-comparable classes.
Forms 3/4/5 flow
Insider trading overview
Net insider flow leans to selling over the last 12 months. Net value: -$207,040,431.
Buys
$0
Insiders: 0
Sells
$207,040,431
Insiders: 9
Net
-$207,040,431
Shares: -1,369,576
Window
Last 12 months
4 rolling buckets
Buy value
Sell value
Shares: 0
Shares: 1,369,576
| Window (months) | Buy shares | Sell shares | Buy value | Sell value | Net value |
|---|---|---|---|---|---|
| 0-3 | 0 | 354,405 | $0 | $44,779,673 | -$44,779,673 |
| 3-6 | 0 | 255,689 | $0 | $35,790,580 | -$35,790,580 |
| 6-9 | 0 | 283,686 | $0 | $49,050,085 | -$49,050,085 |
| 9-12 | 0 | 475,796 | $0 | $77,420,093 | -$77,420,093 |
Reporting owners
Insider holders from Forms 3/4/5
Showing 1-19 of 19 reporting-owner rows connected to INSMED Inc. Open a relationship link for the CIK-to-CIK filing trail.
Rows
19
Largest Forms 3/4/5 holder
William Lewis
Net 12M change
-$207,040,430
Latest report
17 Aug 2026
| Name | Relationship | Holdings Value | Past Year Net Change | Change % | Valuation | Report Date |
|---|---|---|---|---|---|---|
| William Lewis | Chair and CEO, Director | $94,403,772 | -$32,791,057 | -26% | Mixed | 23 Jul 2026 |
| Melvin Sharoky MD | Director | $28,563,602 | -$6,191,750 | -18% | Median | 17 Aug 2026 |
| David R. Brennan | Director | $20,315,397 | Mixed | 13 May 2026 | ||
| David W. J. Mcgirr | Director | $17,196,316 | Mixed | 09 Feb 2026 | ||
| Roger Adsett | Chief Operating Officer | $13,813,858 | -$48,253,224 | -78% | Mixed | 10 Aug 2026 |
| Clarissa Desjardins | Director | $11,992,066 | Mixed | 13 May 2026 | ||
| John Drayton Wise | Chief Commercial Officer | $11,150,460 | Mixed | 05 Feb 2025 | ||
| Carol Schafer | Director | $10,894,029 | Mixed | 13 May 2026 | ||
| Elizabeth M. Anderson | Director | $10,143,799 | -$2,981,600 | -23% | Mixed | 13 May 2026 |
| Leo Lee | Director | $9,479,417 | -$14,692,249 | -61% | Mixed | 13 May 2026 |
| Steinar J. Engelsen | Director | $9,184,561 | Mixed | 01 Nov 2021 | ||
| Martina M.d. Flammer | Chief Medical Officer | $8,481,134 | -$50,264,452 | -86% | Mixed | 06 Aug 2026 |
| Sara Bonstein | Chief Financial Officer | $7,719,262 | -$2,132,573 | -22% | Mixed | 03 Jun 2026 |
| Orlov S. Nicole Schaeffer | Chief People Strategy Officer | $7,423,026 | -$32,243,410 | -81% | Filing P/S | 02 Jan 2026 |
| Christine A. Pellizzari | Chief Legal Officer | $5,466,099 | Mixed | 15 May 2021 | ||
| Michael A. Smith | Chief Legal Officer | $4,168,242 | -$17,490,115 | -81% | Mixed | 22 Jun 2026 |
| John Soriano | Chief Compliance Officer | $2,074,314 | Mixed | 07 Sep 2021 | ||
| Samuele Butera | SVP, GM, Global Respiratory | $1,200,563 | Mixed | 23 Jun 2026 | ||
| Alfred Altomari | Director | $874,247 | Mixed | 13 May 2024 |
Recent insider transactions for INSMED Inc
Showing up to 300 recent insider transactions from the last 12 months.
| Insider | Symbol | Class | Transaction | % | SEC-reported value | SEC-reported price | Shares | Shares owned | Date | Ownership |
|---|---|---|---|---|---|---|---|---|---|---|
| Melvin Sharoky MD | INSM | Common Stock | Sale | -100% | $637,650 | $127.53 | -5,000 | 0 | 17 Aug 2026 | By Padonia, LLC |
| Roger Adsett | INSM | Common Stock | Sale | -70.8% | $31,964,810 | $133.27 | -239,850 | 98,744 | 10 Aug 2026 | Direct |
| Roger Adsett | INSM | Common Stock | Options Exercise | 242.9% | 239,850 | 338,594 | 10 Aug 2026 | Direct | ||
| Roger Adsett | INSM | Stock Option (right to buy) | Options Exercise | -100% | -239,850 | 0 | 10 Aug 2026 | Direct | ||
| Martina M.d. Flammer | INSM | Common Stock | Sale | -31% | $3,494,838 | $128.61 | -27,173 | 60,486 | 06 Aug 2026 | Direct |
| Martina M.d. Flammer | INSM | Common Stock | Options Exercise | 44.9% | 27,173 | 87,659 | 06 Aug 2026 | Direct | ||
| Martina M.d. Flammer | INSM | Stock Option (right to buy) | Options Exercise | -43.3% | -27,173 | 35,580 | 06 Aug 2026 | Direct | ||
| William Lewis | INSM | Common Stock | Sale | -3.97% | $1,134,890 | $106.06 | -10,700 | 259,058 | 23 Jul 2026 | Direct |
| William Lewis | INSM | Common Stock | Options Exercise | 4.13% | 10,700 | 269,758 | 23 Jul 2026 | Direct | ||
| William Lewis | INSM | Stock Option (right to buy) | Options Exercise | -100% | -10,700 | 0 | 23 Jul 2026 | Direct | ||
| William Lewis | INSM | Common Stock | Sale | -3.97% | $1,256,084 | $117.40 | -10,699 | 259,058 | 09 Jul 2026 | Direct |
| William Lewis | INSM | Common Stock | Options Exercise | 4.13% | 10,699 | 269,757 | 09 Jul 2026 | Direct | ||
| William Lewis | INSM | Stock Option (right to buy) | Options Exercise | -70.7% | -10,699 | 4,440 | 09 Jul 2026 | Direct | ||
| Martina M.d. Flammer | INSM | Common Stock | Sale | -16.9% | $1,352,932 | $109.98 | -12,302 | 60,486 | 06 Jul 2026 | Direct |
| Martina M.d. Flammer | INSM | Common Stock | Options Exercise | 20.3% | 12,302 | 72,788 | 06 Jul 2026 | Direct | ||
| Martina M.d. Flammer | INSM | Stock Option (right to buy) | Options Exercise | -73.8% | -12,302 | 4,358 | 06 Jul 2026 | Direct | ||
| William Lewis | INSM | Common Stock | Sale | -7.63% | $2,210,763 | $103.32 | -21,398 | 258,917 | 25 Jun 2026 | Direct |
| William Lewis | INSM | Common Stock | Options Exercise | 8.26% | 21,398 | 280,315 | 25 Jun 2026 | Direct | ||
| William Lewis | INSM | Stock Option (right to buy) | Options Exercise | -70.7% | -21,398 | 8,880 | 25 Jun 2026 | Direct | ||
| Samuele Butera | INSM | Common Stock | Award | 7,342 | 7,342 | 23 Jun 2026 | Direct | |||
| Samuele Butera | INSM | Stock Option (right to buy) | Award | 12,570 | 12,570 | 23 Jun 2026 | Direct | |||
| Michael A. Smith | INSM | Common Stock | Sale | -4.58% | $173,051 | $95.82 | -1,806 | 37,648 | 22 Jun 2026 | Direct |
| William Lewis | INSM | Common Stock | Sale | -2.45% | $612,605 | $94.03 | -6,515 | 258,917 | 08 Jun 2026 | Direct |
| Martina M.d. Flammer | INSM | Common Stock | Sale | -2.98% | $192,823 | $103.78 | -1,858 | 60,486 | 05 Jun 2026 | Direct |
| Roger Adsett | INSM | Common Stock | Sale | -2.35% | $242,380 | $102.27 | -2,370 | 98,603 | 03 Jun 2026 | Direct |
| Sara Bonstein | INSM | Common Stock | Sale | -3.36% | $245,857 | $102.27 | -2,404 | 69,082 | 03 Jun 2026 | Direct |
| Michael A. Smith | INSM | Common Stock | Sale | -5.19% | $220,801 | $102.27 | -2,159 | 39,454 | 03 Jun 2026 | Direct |
| William Lewis | INSM | Common Stock | Sale | -2.79% | $777,763 | $102.27 | -7,605 | 265,432 | 03 Jun 2026 | Direct |
| Martina M.d. Flammer | INSM | Common Stock | Sale | -3.95% | $262,425 | $102.27 | -2,566 | 62,344 | 03 Jun 2026 | Direct |
| Michael A. Smith | INSM | Common Stock | Sale | -12.9% | $666,982 | $108.47 | -6,149 | 41,613 | 22 May 2026 | Direct |
| William Lewis | INSM | Common Stock | Sale | -8.56% | $2,718,224 | $106.33 | -25,564 | 273,037 | 18 May 2026 | Direct |
| William Lewis | INSM | Common Stock | Options Exercise | 3.72% | 10,699 | 298,601 | 18 May 2026 | Direct | ||
| William Lewis | INSM | Stock Option (right to buy) | Options Exercise | -37.6% | -10,699 | 17,760 | 18 May 2026 | Direct | ||
| Martina M.d. Flammer | INSM | Common Stock | Sale | -13.9% | $1,231,702 | $117.54 | -10,479 | 64,910 | 14 May 2026 | Direct |
| Sara Bonstein | INSM | Common Stock | Sale | -10.4% | $961,041 | $116.18 | -8,272 | 71,486 | 13 May 2026 | Direct |
| Carol Schafer | INSM | Common Stock | Award | 5.22% | 3,305 | 66,622 | 13 May 2026 | Direct | ||
| Roger Adsett | INSM | Common Stock | Sale | -5.46% | $678,143 | $116.18 | -5,837 | 100,973 | 13 May 2026 | Direct |
| Elizabeth M. Anderson | INSM | Common Stock | Award | 5.63% | 3,305 | 62,034 | 13 May 2026 | Direct | ||
| Martina M.d. Flammer | INSM | Common Stock | Sale | -9.44% | $897,190 | $114.23 | -7,854 | 75,389 | 13 May 2026 | Direct |
| Michael A. Smith | INSM | Common Stock | Sale | -7.92% | $477,384 | $116.18 | -4,109 | 47,762 | 13 May 2026 | Direct |
| Melvin Sharoky MD | INSM | Common Stock | Award | 1.36% | 3,305 | 246,081 | 13 May 2026 | Direct | ||
| David R. Brennan | INSM | Common Stock | Award | 5.42% | 3,305 | 64,238 | 13 May 2026 | Direct | ||
| Clarissa Desjardins | INSM | Common Stock | Award | 4.93% | 3,305 | 70,312 | 13 May 2026 | Direct | ||
| Leo Lee | INSM | Common Stock | Award | 6.05% | 3,305 | 57,971 | 13 May 2026 | Direct | ||
| William Lewis | INSM | Common Stock | Sale | -4.41% | $1,543,219 | $116.18 | -13,283 | 287,902 | 13 May 2026 | Direct |
| Martina M.d. Flammer | INSM | Common Stock | Sale | -13.5% | $1,300,121 | $100.40 | -12,949 | 83,243 | 11 May 2026 | Direct |
| Martina M.d. Flammer | INSM | Common Stock | Options Exercise | 15.6% | 12,949 | 96,192 | 11 May 2026 | Direct | ||
| Martina M.d. Flammer | INSM | Stock Option (right to buy) | Options Exercise | -100% | -12,949 | 0 | 11 May 2026 | Direct | ||
| William Lewis | INSM | Common Stock | Sale | -3.43% | $1,469,442 | $137.34 | -10,699 | 301,185 | 04 May 2026 | Direct |
| William Lewis | INSM | Common Stock | Options Exercise | 3.55% | 10,699 | 311,884 | 04 May 2026 | Direct |
* marks a reported price that did not pass the local price check.