Insmed INSM Insider Ownership

NASDAQ INSM
$115.63 -2.04 (-1.73%)
At close: Sep 29, 2026 · 4:00 PM EDT

Insider Holdings by Owner

1.84Mn Shares

Insider Ownership Statistics

as of 30 Sep, 2026
Insider Ownership
1.14%
▼-0.032% pp QoQ
Shares Held by Insiders
2.48Mn
filed for Sep 2026
▼-2.74% QoQ
Shares Outstanding
217.35Mn
217,352,000 shares
Direct Holdings
1.79Mn
Indirect: 691.35K
Net Shares Traded (QoQ)
-69.92K
net selling in Sep 2026
Insiders Holding Shares
17
with Form 4 holdings on file

Shares Owned by Insiders

Shares held % of outstanding
Latest —
Average ownership —
Peak ownership —

Shares Purchased/Sold by Insiders

Bought Sold
Latest quarter —
Net over range —
Buying quarters —

Insider Ownership Summary

Quarter ending 30 Sep, 2026

As of September 29, 2026, Insmed's top three insider holders are Steinar J Engelsen (Director, 320.80K shares), William Lewis (Chair And Ceo, 259.06K shares), Melvin Md Sharoky (Director, 246.08K shares).

Form 4 Holdings

Insiders Holding INSM

Insiders 17
Shares held 1.84Mn
Of outstanding 0.847%
# Insider Position Direct Indirect Total Share of Insiders Last Filed
1 Steinar J Engelsen Director 320,802 0 320,802 17.4% 03 Nov, 2021
2 William Lewis Chair And Ceo 259,058 0 259,058 14.1% 24 Jul, 2026
3 Melvin Md Sharoky Director 246,081 0 246,081 13.4% 15 May, 2026
4 John Drayton Wise Chief Commercial Officer 236,999 0 236,999 12.9% 07 Feb, 2025
5 Roger Adsett Chief Operating Officer 98,744 0 98,744 5.4% 12 Aug, 2026
6 David W J Mcgirr Director 44,323 53,400 97,723 5.3% 11 Feb, 2026
7 Clarissa Desjardins Director 70,312 0 70,312 3.8% 15 May, 2026
8 Alfred Altomari Director 69,495 0 69,495 3.8% 15 May, 2024
9 Sara Bonstein Chief Financial Officer 69,082 0 69,082 3.8% 05 Jun, 2026
10 Carol Schafer Director 66,622 0 66,622 3.6% 15 May, 2026
11 Elizabeth M Anderson Director 62,034 0 62,034 3.4% 15 May, 2026
12 Martina M.D. Flammer Chief Medical Officer 60,486 0 60,486 3.3% 07 Aug, 2026
13 Leo Lee Director 57,971 0 57,971 3.1% 15 May, 2026
14 Orlov S Nicole Schaeffer Chief People Strategy Officer 41,754 0 41,754 2.3% 06 Jan, 2026
15 David R Brennan Director 39,238 0 39,238 2.1% 11 Sep, 2026
16 Michael Alexander Smith Chief Legal Officer 37,648 0 37,648 2.0% 24 Jun, 2026
17 Samuele Butera Svp, Gm, Global Respiratory 7,342 0 7,342 0.4% 24 Jun, 2026

Each row is that insider’s most recently reported position, from Form 4 filings over the last 60 months — which is why this total does not tie to the quarterly series above, where a quarter counts only the insiders who filed in it. Shares held through a fund or institutional portfolio are counted on the institutional ownership page instead.

Form 4 Filings

1,749 Insider Transactions

Source SEC Form 4
Latest quarter Sep 2026
Download Data
Date Insider Position Transaction Shares Price Value Shares Held After Ownership
09 Sep, 2026 David R Brennan Director Disposed S 25,000 $124.00 $3.10Mn 39,238 Direct
17 Aug, 2026 Melvin Md Sharoky Director Disposed S 5,000 $127.53 $637.65K 0 Indirect
10 Aug, 2026 Roger Adsett Chief Operating Officer Acquired M 82,280 $13.67 $1.12Mn 181,024 Direct
10 Aug, 2026 Roger Adsett Chief Operating Officer Acquired M 76,600 $17.16 $1.31Mn 257,624 Direct
10 Aug, 2026 Roger Adsett Chief Operating Officer Acquired M 80,970 $30.46 $2.47Mn 338,594 Direct
10 Aug, 2026 Roger Adsett Chief Operating Officer Disposed S 239,850 $133.27 $31.96Mn 98,744 Direct
10 Aug, 2026 Roger Adsett Chief Operating Officer Disposed M 82,280 $0.00 $0 0 Direct
10 Aug, 2026 Roger Adsett Chief Operating Officer Disposed M 76,600 $0.00 $0 0 Direct
10 Aug, 2026 Roger Adsett Chief Operating Officer Disposed M 80,970 $0.00 $0 0 Direct
06 Aug, 2026 Martina M.D. Flammer Chief Medical Officer Acquired M 18,278 $18.95 $346.37K 78,764 Direct
06 Aug, 2026 Martina M.D. Flammer Chief Medical Officer Acquired M 8,895 $25.83 $229.76K 87,659 Direct
06 Aug, 2026 Martina M.D. Flammer Chief Medical Officer Disposed S 8,895 $127.00 $1.13Mn 78,764 Direct
06 Aug, 2026 Martina M.D. Flammer Chief Medical Officer Disposed S 18,278 $129.40 $2.37Mn 60,486 Direct
06 Aug, 2026 Martina M.D. Flammer Chief Medical Officer Disposed M 18,278 $0.00 $0 36,555 Direct
06 Aug, 2026 Martina M.D. Flammer Chief Medical Officer Disposed M 8,895 $0.00 $0 35,580 Direct
23 Jul, 2026 William Lewis Chair And Ceo Acquired M 6,260 $30.46 $190.68K 265,318 Direct
23 Jul, 2026 William Lewis Chair And Ceo Acquired M 4,440 $17.16 $76.19K 269,758 Direct
23 Jul, 2026 William Lewis Chair And Ceo Disposed S 4,828 $105.62 $509.93K 264,930 Direct
23 Jul, 2026 William Lewis Chair And Ceo Disposed S 5,872 $106.43 $624.96K 259,058 Direct
23 Jul, 2026 William Lewis Chair And Ceo Disposed M 6,260 $0.00 $0 0 Direct