William Lewis - 18 Aug 2025 Form 4 Insider Report for INSMED Inc (INSM)

Reporting relationship: Chair and CEO, Director
Issuer ticker: INSM
Reported as of: 18 Aug 2025
Net transaction value: -$806,985
SEC form: 4
Accepted by SEC: 20 Aug 2025, 16:28:49 UTC
Prior SEC filing: 06 Aug 2025
Next SEC filing: 05 Dec 2025
Source filing: View source filing
Reporting owner signature: /s/ William Lewis, by Michael A. Smith as Attorney-in-fact

Key filing fact

William Lewis filed Form 4 for INSMED Inc (INSM) on 20 Aug 2025.

Key facts

This page summarizes William Lewis's Form 4 filing for INSMED Inc (INSM).
5 reported transactions and 1 derivative row are listed below.
Accepted by SEC: 20 Aug 2025, 16:28.

Change

Previous filing in this sequence was filed on 06 Aug 2025.
Current net transaction value: -$806,985.

Research use

This tells you what this filing adds before you inspect full transaction and derivative tables.
You can trace every row back to the original SEC filing document.

Evidence

Filed on Form 4

Ownership activity is grounded in SEC Form 4 disclosures.

View source filing

Reporting Owners (1)

CIK 0001402051 Primary reporting owner

Lewis William

Relationship: Chair and CEO, Director
Address: 700 US HIGHWAY 202/206, BRIDGEWATER
Signature: /s/ William Lewis, by Michael A. Smith as Attorney-in-fact
Signature date: 20 Aug 2025

Reported non-derivative transactions

Shares, units, or other non-derivative securities reported in this filing.

INSM transaction

Common Stock

Options Exercise

Transaction value: $74,485
Shares: +6,865
Change %: +2.9%
Price: $10.85
Shares after: 240,789
Date: 18 Aug 2025
Ownership: By the Katie Procter Dynasty Trust
Footnotes: F1

INSM transaction

Common Stock

Sale

Transaction value: $378,687
Shares: -2,968
Change %: -1.2%
Price: $127.59
Shares after: 237,821
Date: 18 Aug 2025
Ownership: By the Katie Procter Dynasty Trust
Footnotes: F1, F2

INSM transaction

Common Stock

Sale

Transaction value: $319,454
Shares: -2,481
Change %: -1%
Price: $128.76
Shares after: 235,340
Date: 18 Aug 2025
Ownership: By the Katie Procter Dynasty Trust
Footnotes: F1, F3

INSM transaction

Common Stock

Sale

Transaction value: $183,330
Shares: -1,416
Change %: -0.6%
Price: $129.47
Shares after: 233,924
Date: 18 Aug 2025
Ownership: By the Katie Procter Dynasty Trust
Footnotes: F1, F4

INSM holding

Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 303,911
Date: 18 Aug 2025
Ownership: Direct

INSM holding

Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 50,500
Date: 18 Aug 2025
Ownership: By the William Lewis Family Legacy Trust

Reported derivative securities

Options, warrants, convertible securities, or similar derivative positions disclosed in the filing.

INSM transaction Derivative

Stock Option (right to buy)

Options Exercise

Transaction value: $0
Shares: -6,865
Change %: -100%
Price: $0.000000
Shares after: 0
Date: 18 Aug 2025
Ownership: By the Katie Procter Dynasty Trust
Underlying class: Common Stock
Underlying amount: 6,865
Exercise price: $10.85
Footnotes: F1, F5

^* marks a reported price that did not pass the local price check.

Additional SEC filing notes

Filing notes and footnotes

Rule 10b5-1 trading plan

These transactions were reported as open-market trades under a Rule 10b5-1 plan. The plan lets an insider set trading instructions in advance, which can reduce the risk of trading while in possession of material nonpublic information.

Original filing language: transaction made pursuant to a contract, instruction, or written plan intended to satisfy Rule 10b5-1(c).

Explanation of responses 5 footnotes

Footnote F1

This transaction was effected pursuant to a 10b5-1 trading plan adopted by the Reporting Person on September 12, 2024, in accordance with Rule 10b5-1 of the Securities Exchange Act of 1934, as amended.

Footnote F2

This is the weighted average sales price representing 2,968 shares sold at prices ranging from $127.20 to $128.16 per share. The Reporting Person undertakes to provide to the SEC staff, the issuer, or a security holder of the issuer the number of shares sold at each price within the price range upon request.

Footnote F3

This is the weighted average sales price representing 2,481 shares sold at prices ranging from $128.26 to $129.21 per share. The Reporting Person undertakes to provide to the SEC staff, the issuer, or a security holder of the issuer the number of shares sold at each price within the price range upon request.

Footnote F4

This is the weighted average sales price representing 1,416 shares sold at prices ranging from $129.26 to $129.95 per share. The Reporting Person undertakes to provide to the SEC staff, the issuer, or a security holder of the issuer the number of shares sold at each price within the price range upon request.

Footnote F5

The options became exercisable based on the following vesting schedule: 25% vested on the first anniversary of the grant date and an additional 12.5% vested on each sixth month anniversary date thereafter through the fourth anniversary of the date of grant. All options are currently exercisable.

SEC remarks

Exhibit List - Exhibit 24 - Power of Attorney