Institutional Owner T. Rowe Price Discloses 11.23M INSM Shares, 5.9% Stake

Rhea-AI Filing Summary

T. Rowe Price Associates, Inc. reports beneficial ownership of 11,230,934 shares of Insmed Inc. common stock, representing 5.9% of the class. The filing shows sole voting power over 10,918,453 shares and sole dispositive power over 11,188,173 shares, with no shared voting or dispositive powers. The firm states these shares are held in the ordinary course of business and were not acquired to change or influence control of the issuer. The disclosure identifies T. Rowe Price as an investment adviser and clarifies there is no group affiliation noted. This is a material institutional ownership disclosure but does not, by itself, indicate an intent to exert control.

Positive

• Material institutional disclosure: Ownership of 11,230,934 shares equals 5.9% of Insmed, a level that requires public reporting.
• Concentrated sole authority: The filer reports sole voting power for 10,918,453 shares and sole dispositive power for 11,188,173 shares, providing clarity on control of the holdings.
• Passive intent stated: The filing certifies shares are held in the ordinary course and not acquired to change control, reducing immediate activist risk.

Negative

• None.

Insights

Securities Analyst

TL;DR: T. Rowe Price reports a material passive stake in Insmed—11.23M shares, 5.9% of the class, with substantial sole voting and dispositive power.

The filing documents meaningful institutional ownership that crosses the 5% disclosure threshold, making it reportable and visible to the market. Reported figures show concentrated sole voting and dispositive authority rather than shared control, which simplifies the ownership profile. The certification that holdings are in the ordinary course and not for control indicates a passive investment posture. For investors, this clarifies who holds significant exposure to Insmed without signaling activist intentions.

Corporate Governance Expert

TL;DR: Clear disclosure of concentrated sole voting and dispositive power; filing affirms no intent to influence control.

The Schedule 13G classification and the accompanying certification reflect an investment-adviser reporting style focused on transparency. The absence of shared powers and the explicit denial of control intent reduce immediate governance concerns. However, a near-6% stake is large enough to warrant ongoing monitoring for any changes in filing status or shifts toward more active engagement that would require different disclosures.

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. 14)

INSMED INC

(Name of Issuer)

COMMON STOCK

(Title of Class of Securities)

457669307

(CUSIP Number)

06/30/2025

(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)

SCHEDULE 13G

CUSIP No. 457669307

1

Names of Reporting Persons

T. Rowe Price Associates, Inc.

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

MARYLAND

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 10,918,453.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 11,188,173.00
8	Shared Dispositive Power 0.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

11,230,934.00

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)

5.9 %

12

Type of Reporting Person (See Instructions)

IA

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, 08807
Item 2.
(a)	Name of person filing: T. Rowe Price Associates, Inc.
(b)	Address or principal business office or, if none, residence: 1307 Point Street, Baltimore, MD 21231
(c)	Citizenship: Maryland
(d)	Title of class of securities: COMMON STOCK
(e)	CUSIP No.: 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: 11230934
(b)	Percent of class: 5.9 %
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: 10918453
	(ii) Shared power to vote or to direct the vote: 0
	(iii) Sole power to dispose or to direct the disposition of: 11188173
	(iv) Shared power to dispose or to direct the disposition of: 0
Item 5.	Ownership of 5 Percent or Less of a Class.
Item 6.	Ownership of more than 5 Percent on Behalf of Another Person.
	Not Applicable
Item 7.	Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.
	Not Applicable
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. T. Rowe Price Associates, Inc. hereby declares and affirms that the filing of Schedule 13G shall not be construed as an admission that Price Associates is the beneficial owner of the securities referred to, which beneficial ownership is expressly denied.

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.

T. Rowe Price Associates, Inc.

Signature:	Ellen York
Name/Title:	Vice President
Date:	08/14/2025

FAQ

What stake does T. Rowe Price hold in Insmed (INSM)?

T. Rowe Price Associates reports beneficial ownership of 11,230,934 shares, representing 5.9% of Insmed common stock.

How much voting and dispositive power does T. Rowe Price report for INSM shares?

The filing reports sole voting power over 10,918,453 shares and sole dispositive power over 11,188,173 shares, with no shared powers.

Is T. Rowe Price seeking to influence control of Insmed?

The filing certifies the shares are held in the ordinary course of business and were not acquired to change or influence control of the issuer.

How is T. Rowe Price classified in the filing?

T. Rowe Price Associates is identified as an investment adviser (IA) in the Schedule 13G.

Who signed the Schedule 13G for T. Rowe Price?

The filing is signed by Ellen York, Vice President of T. Rowe Price Associates, Inc.