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INSM Insider Trading & Form 4 Activity

INSMED Inc
Last filing: Jun 10, 2026·13 days ago
BEARISH · LAST 90 DAYS
0%
buyers
$0
0 buys
$5.1M
8 sells
-$5.1M
net selling
4
insiders
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ACTIVE SELLING CLUSTER

4 insiders sold a combined $3.7M of INSM on May 13, 2026.

Bonstein Sara, Smith Michael Alexander, Lewis William, Adsett Roger

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Net flow — last 12 months

Monthly net of insider buys minus sells. Green months indicate net buying; red months indicate net selling.

Most active insiders

Ranked by total transaction value over the last 90 days.

INSIDERBOUGHTSOLDNET
Lewis William
Chair and CEO
$7.1M
-$7.1M
Flammer Martina M.D.
Chief Medical Officer
$3.9M
-$3.9M
Smith Michael Alexander
Chief Legal Officer
$1.4M
-$1.4M
Bonstein Sara
Chief Financial Officer
$1.2M
-$1.2M
Adsett Roger
Chief Operating Officer
$921K
-$921K
Desjardins Clarissa
Insider
$0
Brennan David R
Insider
$0
Schafer Carol
Insider
$0

Recent transactions

Every Form 4 transaction for INSM, newest first.

SELL10b5-1
Lewis William · Chair and CEO
Tx Jun 8·Filed Jun 10·EDGAR ↗
6,515 sh @ $94.03
$613K
SELL10b5-1
Flammer Martina M.D. · Chief Medical Officer
Tx Jun 5·Filed Jun 5·EDGAR ↗
1,858 sh @ $103.78
$193K
SELL10b5-1
Flammer Martina M.D. · Chief Medical Officer
Tx Jun 3·Filed Jun 5·EDGAR ↗
2,566 sh @ $102.27
$262K
SELL
Smith Michael Alexander · Chief Legal Officer
Tx Jun 3·Filed Jun 5·EDGAR ↗
2,159 sh @ $102.27
$221K
SELL
Lewis William · Chair and CEO
Tx Jun 3·Filed Jun 5·EDGAR ↗
7,605 sh @ $102.27
$778K
SELL
Adsett Roger · Chief Operating Officer
Tx Jun 3·Filed Jun 5·EDGAR ↗
2,370 sh @ $102.27
$242K
SELL
Bonstein Sara · Chief Financial Officer
Tx Jun 3·Filed Jun 5·EDGAR ↗
2,404 sh @ $102.27
$246K
SELL10b5-1
Smith Michael Alexander · Chief Legal Officer
Tx May 22·Filed May 22·EDGAR ↗
6,149 sh @ $108.47
$667K
SELL10b5-1
Lewis William · Chair and CEO
Tx May 18·Filed May 20·EDGAR ↗
5,753 sh @ $105.32
$606K
EXERCISE10b5-1
Lewis William · Chair and CEO
Tx May 18·Filed May 20·EDGAR ↗
4,440 sh @ $17.16
$76K
SELL10b5-1
Lewis William · Chair and CEO
Tx May 18·Filed May 20·EDGAR ↗
11,836 sh @ $106.39
$1.3M
EXERCISE10b5-1
Lewis William · Chair and CEO
Tx May 18·Filed May 20·EDGAR ↗
6,259 sh @ $30.46
$191K
SELL10b5-1
Lewis William · Chair and CEO
Tx May 18·Filed May 20·EDGAR ↗
7,975 sh @ $106.97
$853K
SELL10b5-1
Flammer Martina M.D. · Chief Medical Officer
Tx May 14·Filed May 15·EDGAR ↗
10,479 sh @ $117.54
$1.2M
AWARD
Desjardins Clarissa · Insider
Tx May 13·Filed May 15·EDGAR ↗
3,305 sh
SELL
Bonstein Sara · Chief Financial Officer
Tx May 13·Filed May 15·EDGAR ↗
8,272 sh @ $116.18
$961K
AWARD
Brennan David R · Insider
Tx May 13·Filed May 15·EDGAR ↗
3,305 sh
SELL
Smith Michael Alexander · Chief Legal Officer
Tx May 13·Filed May 15·EDGAR ↗
4,109 sh @ $116.18
$477K
AWARD
Schafer Carol · Insider
Tx May 13·Filed May 15·EDGAR ↗
3,305 sh
AWARD
Sharoky Melvin MD · Insider
Tx May 13·Filed May 15·EDGAR ↗
3,305 sh
SELL10b5-1
Flammer Martina M.D. · Chief Medical Officer
Tx May 13·Filed May 15·EDGAR ↗
4,470 sh @ $112.76
$504K
SELL10b5-1
Flammer Martina M.D. · Chief Medical Officer
Tx May 13·Filed May 15·EDGAR ↗
3,384 sh @ $116.18
$393K
SELL
Lewis William · Chair and CEO
Tx May 13·Filed May 15·EDGAR ↗
13,283 sh @ $116.18
$1.5M
AWARD
Anderson Elizabeth M · Insider
Tx May 13·Filed May 15·EDGAR ↗
3,305 sh
SELL
Adsett Roger · Chief Operating Officer
Tx May 13·Filed May 15·EDGAR ↗
5,837 sh @ $116.18
$678K
AWARD
Lee Leo · Insider
Tx May 13·Filed May 15·EDGAR ↗
3,305 sh
SELL10b5-1
Flammer Martina M.D. · Chief Medical Officer
Tx May 11·Filed May 13·EDGAR ↗
830 sh @ $101.18
$84K
SELL10b5-1
Flammer Martina M.D. · Chief Medical Officer
Tx May 11·Filed May 13·EDGAR ↗
12,119 sh @ $100.35
$1.2M
EXERCISE10b5-1
Flammer Martina M.D. · Chief Medical Officer
Tx May 11·Filed May 13·EDGAR ↗
12,949 sh @ $17.07
$221K
SELL10b5-1
Lewis William · Chair and CEO
Tx May 4·Filed May 6·EDGAR ↗
5,318 sh @ $137.01
$729K
SELL10b5-1
Lewis William · Chair and CEO
Tx May 4·Filed May 6·EDGAR ↗
599 sh @ $135.18
$81K
SELL10b5-1
Lewis William · Chair and CEO
Tx May 4·Filed May 6·EDGAR ↗
381 sh @ $139.60
$53K
EXERCISE10b5-1
Lewis William · Chair and CEO
Tx May 4·Filed May 6·EDGAR ↗
4,440 sh @ $17.16
$76K
EXERCISE10b5-1
Lewis William · Chair and CEO
Tx May 4·Filed May 6·EDGAR ↗
6,259 sh @ $30.46
$191K
SELL10b5-1
Lewis William · Chair and CEO
Tx May 4·Filed May 6·EDGAR ↗
433 sh @ $134.18
$58K
SELL10b5-1
Lewis William · Chair and CEO
Tx May 4·Filed May 6·EDGAR ↗
1,247 sh @ $139.09
$173K
SELL10b5-1
Lewis William · Chair and CEO
Tx May 4·Filed May 6·EDGAR ↗
2,721 sh @ $137.86
$375K

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About INSM insider trading data

Form 4 is the SEC filing required when an officer, director, or 10% owner of a public company buys or sells the company's stock. By law, these filings must be submitted within two business days of the trade. Tracenotes pulls every Form 4 filing for INSM from EDGAR, parses it, and surfaces the activity on this page.

What insider buying tells you. Open-market purchases by insiders are widely studied as a meaningful signal. Unlike stock awards (which are compensation, not conviction), an executive spending their own money to buy shares of the company they run is a vote of confidence. Studies have found insider-buying clusters — three or more insiders buying within a short window — outperform the broader market over the following year.

What insider selling tells you. Selling is noisier. Many sales are pre-scheduled under SEC Rule 10b5-1 plans, which let insiders sell on a fixed schedule regardless of company news. We label these "10b5-1" so you can see them. Discretionary sales — sales not tied to a plan — are more meaningful, especially when multiple insiders sell in quick succession.

Tracenotes methodology. We scan EDGAR daily for new Form 4 filings, parse them into individual transactions, and detect clusters when three or more distinct insiders buy or sell within a 14-day window. The data on this page covers the last 12 months. For deeper analysis, Tracenotes also runs language-change detection on 10-K and 10-Q filings — that's our core product.

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Frequently asked questions

What is a Form 4 filing?

Form 4 is the SEC disclosure required when a company insider — an officer, director, or 10% owner — buys or sells the company's stock. By law these filings must be submitted within two business days of the trade.

Is insider buying INSM always bullish?

Open-market purchases by insiders are widely viewed as a bullish signal because executives are spending their own money. Stock awards and option exercises are part of compensation and don't carry the same weight, which is why we treat them separately on this page.

What is a 10b5-1 trade?

A trade made under SEC Rule 10b5-1, which lets insiders pre-schedule sales weeks or months in advance. These sales execute on a fixed plan regardless of company news, so they're a weaker signal than discretionary sales. We label them with a "10b5-1" tag.

What is an insider cluster?

A cluster is when three or more distinct insiders buy or sell within a 14-day window. Clusters are studied as stronger signals than single trades because multiple people independently reach the same view. We surface active clusters on INSMED Inc (INSM) when they form.

Where does INSM insider trading data come from?

Every Form 4 filing for INSM is sourced directly from SEC EDGAR. Tracenotes scans EDGAR daily, parses each Form 4 into individual transactions, and updates this page within hours of new filings.

Nothing on this page constitutes investment advice. Form 4 data is sourced from SEC EDGAR and provided for research purposes only.

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