FMR LLC holds 13.15M shares of INSMED (NASDAQ: INSM) via Schedule 13G

Rhea-AI Filing Summary

FMR LLC reports beneficial ownership of 13,145,166.52 shares of INSMED INC common stock, representing 6.1% of the class as of 03/31/2026. The filing (Schedule 13G) lists sole dispositive power for 13,145,166.52 shares and zero shared voting/dispositive power. The CUSIP is 457669307 and the filing identifies Abigail P. Johnson in a related capacity.

Insights

Institutional Ownership Analyst

Large passive stake reported by FMR LLC; position quantified at 13,145,166.52 shares (6.1%).

FMR LLC's Schedule 13G discloses beneficial ownership of 13,145,166.52 shares with sole dispositive power for the same amount and no shared voting power. The filing format and Item 6 language indicate aggregated holdings on behalf of multiple clients.

Future ownership changes will appear in amendments; the filing ties the position to 03/31/2026 and cites Exhibit 99 and an Exhibit 24 power of attorney for signature authority.

Key Figures

Beneficial ownership: 13,145,166.52 shares Percent of class: 6.1% CUSIP: 457669307 +2 more

5 metrics

Beneficial ownership 13,145,166.52 shares as of 03/31/2026

Percent of class 6.1% percentage of outstanding common stock

CUSIP 457669307 INSMED INC common stock identifier

Sole dispositive power 13,145,166.52 shares amount with sole power to dispose

Reporting date 03/31/2026 date tied to the ownership figures

Key Terms

Schedule 13G, Beneficial ownership, Sole dispositive power, 13d-1(k)(1) agreement

4 terms

Schedule 13G regulatory

"Filing type shown as SCHEDULE 13G in the header"

A Schedule 13G is a formal document that investors file with the government when they acquire a large ownership stake in a company, usually for investment purposes rather than control. It helps keep the public informed about who owns significant parts of a company's shares, which can influence how the company is managed and how investors make decisions. Filing this schedule is important for transparency and understanding the ownership landscape of publicly traded companies.

Beneficial ownership financial

"Item 4. | Ownership (a) | Amount beneficially owned: 13145166.52"

Beneficial ownership means the person or entity that actually enjoys the benefits of owning shares or other assets — such as receiving dividends, voting rights, or price gains — even if the legal title is held in another name. For investors it matters because knowing who truly controls and profits from a company reveals who can influence decisions, exposes potential conflicts of interest or hidden concentration of power, and affects transparency and risk in the stock.

Sole dispositive power financial

"Item 4. (iii) Sole power to dispose: 13145166.52"

Sole dispositive power is the exclusive legal authority to decide what happens to a security — for example, whether to sell, transfer, or retain shares — without needing anyone else’s permission. Investors care because it signals who truly controls the economic outcome of an investment: like holding the only key to a safe, the holder can realize gains or losses and may trigger regulatory reporting, insider rules, or influence over corporate ownership.

13d-1(k)(1) agreement regulatory

"Exhibit 99 for 13d-1(k)(1) agreement referenced"

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

INSMED INC

(Name of Issuer)

COMMON STOCK

(Title of Class of Securities)

457669307

(CUSIP Number)

03/31/2026

(Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

Rule 13d-1(b)

Rule 13d-1(c)

Rule 13d-1(d)

schemaVersion:

SCHEDULE 13G

CUSIP Number(s): 457669307

1

Names of Reporting Persons

FMR LLC

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 12,896,724.87
6	Shared Voting Power 0.00
7	Sole Dispositive Power 13,145,166.52
8	Shared Dispositive Power 0.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

13,145,166.52

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

6.1 %

12

Type of Reporting Person (See Instructions)

HC

SCHEDULE 13G

CUSIP Number(s): 457669307

1

Names of Reporting Persons

Abigail P. Johnson

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

UNITED STATES

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 13,145,166.52
8	Shared Dispositive Power 0.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

13,145,166.52

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

6.1 %

12

Type of Reporting Person (See Instructions)

IN

SCHEDULE 13G

Item 1.
(a)	Name of issuer: INSMED INC
(b)	Address of issuer's principal executive offices: 700 US HIGHWAY 202/206,BRIDGEWATER,NJ,USA,08807
Item 2.
(a)	Name of person filing: FMR LLC
(b)	Address or principal business office or, if none, residence: 245 Summer Street, Boston, Massachusetts 02210
(c)	Citizenship: Not applicable
(d)	Title of class of securities: COMMON STOCK
(e)	CUSIP Number(s): 457669307
Item 3.	If this statement is filed pursuant to §§ 240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:
(a)	Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o);
(b)	Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c);
(c)	Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c);
(d)	Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8);
(e)	An investment adviser in accordance with § 240.13d-1(b)(1)(ii)(E);
(f)	An employee benefit plan or endowment fund in accordance with § 240.13d-1(b)(1)(ii)(F);
(g)	A parent holding company or control person in accordance with § 240.13d-1(b)(1)(ii)(G);
(h)	A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);
(i)	A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);
(j)	A non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J). If filing as a non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J), please specify the type of institution:
(k)	Group, in accordance with Rule 240.13d-1(b)(1)(ii)(K).
Item 4.	Ownership
(a)	Amount beneficially owned: 13145166.52
(b)	Percent of class: 6.1 %
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: Please see the responses to Items 5 and 6 on the cover page.
	(ii) Shared power to vote or to direct the vote: 0.00
	(iii) Sole power to dispose or to direct the disposition of: 13145166.52
	(iv) Shared power to dispose or to direct the disposition of: 0.00
Item 5.	Ownership of 5 Percent or Less of a Class.
	Not Applicable
Item 6.	Ownership of more than 5 Percent on Behalf of Another Person.
	If any other person is known to have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, such securities, a statement to that effect should be included in response to this item and, if such interest relates to more than 5 percent of the class, such person should be identified. A listing of the shareholders of an investment company registered under the Investment Company Act of 1940 or the beneficiaries of employee benefit plan, pension fund or endowment fund is not required. One or more other persons are known to have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, the COMMON STOCK of INSMED INC. No one other person's interest in the COMMON STOCK of INSMED INC is more than five percent of the total outstanding COMMON STOCK.
Item 7.	Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.
	If a parent holding company has filed this schedule, pursuant to Rule 13d-1(b)(ii)(G), so indicate under Item 3(g) and attach an exhibit stating the identity and the Item 3 classification of the relevant subsidiary. If a parent holding company has filed this schedule pursuant to Rule 13d-1(c) or Rule 13d-1(d), attach an exhibit stating the identification of the relevant subsidiary. See attached Exhibit 99.
Item 8.	Identification and Classification of Members of the Group.
	Not Applicable
Item 9.	Notice of Dissolution of Group.
	Not Applicable

Item 10.

Certifications:

By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under ?? 240.14a-11.

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

FMR LLC

Signature:	Richard Bourgelas
Name/Title:	Duly authorized under Power of Attorney effective as of April 13, 2026, by and on behalf of FMR LLC and its direct and indirect subsidiaries*
Date:	05/05/2026

Abigail P. Johnson

Signature:	Richard Bourgelas
Name/Title:	Duly authorized under Power of Attorney effective as of April 13, 2026, by and on behalf of Abigail P. Johnson*
Date:	05/05/2026

Comments accompanying signature: *This power of attorney is incorporated herein by reference to Exhibit 24 to the Schedule 13G filed by FMR LLC on April 29,2026, accession number: 0000315066-26-000738.

Exhibit Information

Please see Exhibit 99 for 13d-1(k) (1) agreement.

FAQ

What stake does FMR LLC report in INSM (INSMED INC)?

FMR LLC reports 13,145,166.52 shares, or 6.1% of INSMED common stock. The Schedule 13G lists sole dispositive power for 13,145,166.52 shares and zero shared voting/dispositive power, with the position tied to the 03/31/2026 reporting date.

Does the filing show who at FMR controls the INSM stake?

The filing names Abigail P. Johnson and FMR LLC; Richard Bourgelas signed under power of attorney. Abigail P. Johnson is listed in the cover data and signatures reference a power of attorney incorporated by Exhibit 24 (see Exhibit 99 for subsidiary/authorization details).

What voting or dispositive powers does FMR LLC report for these shares?

FMR LLC reports sole dispositive power for 13,145,166.52 shares and zero shared voting power. The Schedule 13G response shows sole power to dispose and directs readers to Items 5 and 6 on the cover for voting-power detail.

What is the reporting date and CUSIP on the Schedule 13G for INSM?

The reporting date shown is 03/31/2026 and the CUSIP is 457669307. These identifiers appear on the cover section and tie the disclosed 13,145,166.52-share position to that specific record date.

Is the FMR LLC filing an active or passive disclosure for INSMED?

The filing is a Schedule 13G disclosure showing reported beneficial ownership; classification details are on the form. The Schedule 13G format typically indicates passive or institutional reporting; the excerpt references Exhibit 99 for a 13d-1(k)(1) agreement but does not change the stated share counts.