Artisan Partners Asset Management Inc., together with related entities, reports passive ownership of 1,660,307 common shares of iRhythm Holdings, Inc. This represents 5.1% of the outstanding common shares, based on 32,862,408 shares outstanding as of April 23, 2026. The group reports no sole voting or dispositive power over the shares. Instead, it has shared voting power over 1,529,086 shares and shared dispositive power over 1,660,307 shares.
The shares are held by Artisan Partners Limited Partnership, an investment adviser registered under section 203 of the Investment Advisers Act of 1940, on behalf of its discretionary clients. Those clients, rather than the Artisan entities, are entitled to dividends and sale proceeds, and to the knowledge of the filers, no individual client has an economic interest in more than 5% of iRhythm’s common shares.
Positive
None.
Negative
None.
Key Figures
Beneficially owned shares:1,660,307 sharesPercent of class:5.1%Shares outstanding:32,862,408 shares+2 more
5 metrics
Beneficially owned shares1,660,307 sharesCommon shares of iRhythm Holdings beneficially owned by Artisan entities
Percent of class5.1%Portion of iRhythm common shares represented by 1,660,307 shares
Shares outstanding32,862,408 sharesiRhythm common shares outstanding as of 04/23/2026
Shared voting power1,529,086 sharesShares over which Artisan entities share voting power
Shared dispositive power1,660,307 sharesShares over which Artisan entities share dispositive power
Key Terms
beneficially owned, shared voting power, shared dispositive power, Investment Advisers Act of 1940, +1 more
Beneficially owned describes securities or assets where a person has the economic rights and control—such as the right to receive dividends and to direct voting—even if legal title is held in another name. Think of it like having the keys and using a car that’s registered to someone else: you get the benefits and make decisions. Investors care because beneficial ownership reveals who truly controls value and voting power, affecting corporate decisions and takeover dynamics.
shared voting powerfinancial
"Shared Voting Power 1,529,086.00"
Shared voting power occurs when two or more parties jointly have the right to vote or decide how a block of company shares is cast, like co-owners who must agree before moving a piece of furniture. Investors care because who controls voting rights affects board elections, major corporate decisions and takeover outcomes, and shared control can alter regulatory disclosures and the practical influence any holder has over a company’s direction and value.
shared dispositive powerfinancial
"Shared Dispositive Power 1,660,307.00"
Investment Advisers Act of 1940regulatory
"an investment adviser registered under section 203 of the Investment Advisers Act of 1940"
A U.S. federal law that sets rules for people and firms who give investment advice, requiring them to register with regulators, be honest about conflicts, keep records, and follow basic standards of care. It matters to investors because those rules act like licensing and consumer protections — similar to having safety standards for a mechanic — helping ensure advisers act in clients’ financial interests and reducing the risk of fraud or misuse of funds.
discretionary clientsfinancial
"The shares reported herein have been acquired on behalf of discretionary clients of APLP."
FAQ
What percentage of iRhythm Holdings (IRTC) shares does Artisan Partners report owning?
Artisan Partners reports beneficial ownership of 5.1% of iRhythm Holdings’ common shares, based on 32,862,408 shares outstanding as of April 23, 2026. This reflects shares held for discretionary clients of Artisan Partners Limited Partnership.
How many iRhythm Holdings (IRTC) shares are beneficially owned by Artisan Partners?
Artisan Partners and related entities report 1,660,307 iRhythm common shares beneficially owned. They have shared dispositive power over all 1,660,307 shares and shared voting power over 1,529,086 shares, with no sole voting or dispositive power.
Who actually receives dividends and sale proceeds from the iRhythm (IRTC) shares held by Artisan Partners?
Dividends and sale proceeds from the 1,660,307 iRhythm shares are payable to discretionary clients of Artisan Partners Limited Partnership. The filing states that persons other than APLP are entitled to all dividends and sale proceeds from these shares.
Does any single Artisan Partners client hold more than 5% of iRhythm (IRTC)?
According to the filing, no individual client of Artisan Partners Limited Partnership is known to have an economic interest in more than 5% of iRhythm’s common shares. The 5.1% interest is spread across multiple discretionary clients.
What kind of entity is Artisan Partners Limited Partnership in relation to iRhythm (IRTC)?
Artisan Partners Limited Partnership is described as an investment adviser registered under section 203 of the Investment Advisers Act of 1940. It acquired the iRhythm shares on behalf of its discretionary clients, over which it holds shared voting and dispositive powers.
Where are the Artisan entities that filed regarding iRhythm (IRTC) based?
Artisan Partners Asset Management Inc., Artisan Partners Holdings LP, Artisan Investments GP LLC, and Artisan Partners Limited Partnership are all organized in Delaware and share a principal office at 875 East Wisconsin Avenue, Suite 800, Milwaukee, WI 53202.
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
SCHEDULE 13G
UNDER THE SECURITIES EXCHANGE ACT OF 1934
iRhythm Holdings, Inc.
(Name of Issuer)
Common Shares
(Title of Class of Securities)
450056106
(CUSIP Number)
06/30/2026
(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):
450056106
1
Names of Reporting Persons
Artisan Partners Asset Management 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
DELAWARE
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
0.00
6
Shared Voting Power
1,529,086.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
1,660,307.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
1,660,307.00
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)
5.1 %
12
Type of Reporting Person (See Instructions)
HC
Comment for Type of Reporting Person: (g) Artisan Partners Holdings LP is the sole limited partner of Artisan Partners Limited Partnership and the sole member of Artisan Investments GP LLC; Artisan Investments GP LLC is the general partner of Artisan Partners Limited Partnership; Artisan Partners Asset Management Inc. is the general partner of Artisan Partners Holdings LP.
SCHEDULE 13G
CUSIP Number(s):
450056106
1
Names of Reporting Persons
Artisan Partners Holdings LP
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
0.00
6
Shared Voting Power
1,529,086.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
1,660,307.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
1,660,307.00
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)
5.1 %
12
Type of Reporting Person (See Instructions)
HC
Comment for Type of Reporting Person: (g) Artisan Partners Holdings LP is the sole limited partner of Artisan Partners Limited Partnership and the sole member of Artisan Investments GP LLC; Artisan Investments GP LLC is the general partner of Artisan Partners Limited Partnership; Artisan Partners Asset Management Inc. is the general partner of Artisan Partners Holdings LP.
SCHEDULE 13G
CUSIP Number(s):
450056106
1
Names of Reporting Persons
Artisan Investments GP 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
0.00
6
Shared Voting Power
1,529,086.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
1,660,307.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
1,660,307.00
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)
5.1 %
12
Type of Reporting Person (See Instructions)
HC
Comment for Type of Reporting Person: (g) Artisan Partners Holdings LP is the sole limited partner of Artisan Partners Limited Partnership and the sole member of Artisan Investments GP LLC; Artisan Investments GP LLC is the general partner of Artisan Partners Limited Partnership; Artisan Partners Asset Management Inc. is the general partner of Artisan Partners Holdings LP.
SCHEDULE 13G
CUSIP Number(s):
450056106
1
Names of Reporting Persons
Artisan Partners Limited Partnership
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
0.00
6
Shared Voting Power
1,529,086.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
1,660,307.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
1,660,307.00
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)
5.1 %
12
Type of Reporting Person (See Instructions)
IA
Comment for Type of Reporting Person: (e) Artisan Partners Limited Partnership is an investment adviser registered under section 203 of the Investment Advisers Act of 1940.
(g) Artisan Partners Holdings LP is the sole limited partner of Artisan Partners Limited Partnership and the sole member of Artisan Investments GP LLC; Artisan Investments GP LLC is the general partner of Artisan Partners Limited Partnership; Artisan Partners Asset Management Inc. is the general partner of Artisan Partners Holdings LP.
SCHEDULE 13G
Item 1.
(a)
Name of issuer:
iRhythm Holdings, Inc.
(b)
Address of issuer's principal executive offices:
699 8th Street Suite 600, San Francisco, California 94103
Address or principal business office or, if none, residence:
APAM, Artisan Holdings, Artisan Investments, and APLP are all located at:
875 East Wisconsin Avenue, Suite 800
Milwaukee, WI 53202
(c)
Citizenship:
APAM is a Delaware corporation; Artisan Holdings is a Delaware limited partnership; Artisan Investments is a Delaware limited liability company; APLP is a Delaware limited partnership
(d)
Title of class of securities:
Common Shares
(e)
CUSIP Number(s):
450056106
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:
1,660,307
(b)
Percent of class:
5.1% (based on 32,862,408 shares outstanding as of 04/23/2026)
(c)
Number of shares as to which the person has:
(i) Sole power to vote or to direct the vote:
None
(ii) Shared power to vote or to direct the vote:
1,529,086
(iii) Sole power to dispose or to direct the disposition of:
None
(iv) Shared power to dispose or to direct the disposition of:
1,660,307
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.
The shares reported herein have been acquired on behalf of discretionary clients of APLP. Persons other than APLP are entitled to receive all dividends from, and proceeds from the sale of, those shares. None of those persons, to the knowledge of APAM, Artisan Holdings, Artisan Investments, or APLP has an economic interest in more than 5% of the class.
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.
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.
Artisan Partners Asset Management Inc.
Signature:
/s/ Gregory K. Ramirez
Name/Title:
Gregory K. Ramirez, Executive Vice President of Artisan Partners Asset Management Inc.
Date:
08/13/2026
Artisan Partners Holdings LP
Signature:
/s/ Gregory K. Ramirez
Name/Title:
Gregory K. Ramirez, Executive Vice President of Artisan Partners Asset Management Inc., as the general partner of Artisan Partners Holdings LP
Date:
08/13/2026
Artisan Investments GP LLC
Signature:
/s/ Gregory K. Ramirez
Name/Title:
Gregory K. Ramirez, Vice President of Artisan Investments GP LLC
Date:
08/13/2026
Artisan Partners Limited Partnership
Signature:
/s/ Gregory K. Ramirez
Name/Title:
Gregory K. Ramirez, Vice President of Artisan Investments GP LLC, as the general partner of Artisan Partners Limited Partnership
Date:
08/13/2026
Exhibit Information
Exhibit Index
Exhibit 1 - Joint Filing Agreement dated 08/13/2026 by and among Artisan Partners Asset Management Inc., Artisan Partners Holdings LP, Artisan Investments GP LLC, and Artisan Partners Limited Partnership.
