iRhythm Holdings, Inc. ownership disclosure: RTW Investments, LP and Roderick Wong report beneficial ownership of 1,668,500 shares of Common Stock, representing 5.2% of the class. The filing cites 32,316,760 Shares outstanding as of February 12, 2026. The statement is signed by Dr. Wong on May 15, 2026.
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Insights
RTW reports a >5% passive stake in iRhythm via shared power.
RTW Investments and Dr. Roderick Wong report 1,668,500 shares, equal to 5.2% of the outstanding common stock stated as 32,316,760 shares as of February 12, 2026. The filing attributes shared voting and dispositive power to the reporting persons.
Ownership is reported on a Schedule 13G, typically indicating passive investment intent; future filings would show changes. Cash‑flow treatment and any plans for disposition are not stated in the excerpt.
Filing follows Schedule 13G conventions and includes a joint filing agreement.
The statement identifies RTW Funds as the holders and Dr. Wong as managing partner, and it incorporates the company’s Form 10‑K outstanding share count for the February 12, 2026 anchor. It discloses shared voting and shared dispositive power of 1,668,500 shares.
Stakeholders should note the filing’s signature date of May 15, 2026; subsequent Schedule 13D/13G or Form 4 filings would provide any material change in intent or transactions.
Key Figures
Shares reported:1,668,500 sharesPercent of class:5.2%Shares outstanding:32,316,760 Shares+1 more
4 metrics
Shares reported1,668,500 sharesAmount beneficially owned by RTW Investments and Roderick Wong
Percent of class5.2%Percent of common stock based on disclosed outstanding shares
Shares outstanding32,316,760 SharesShares outstanding as of <date>February 12, 2026</date> per the company’s Form 10‑K
Signature date05/15/2026Date the Schedule 13G was signed by Roderick Wong, M.D.
"Item 2. indicates the statement is filed as a Schedule 13G"
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.
Shared Dispositive Powerfinancial
"Rows show Shared Dispositive Power 1,668,500.00 for RTW and Dr. Wong"
Beneficially ownedregulatory
"Item 4(a) references the amount 'beneficially owned' in cover page rows"
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.
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
SCHEDULE 13G
UNDER THE SECURITIES EXCHANGE ACT OF 1934
iRhythm Holdings, Inc.
(Name of Issuer)
Common Stock, $0.001 par value
(Title of Class of Securities)
450056106
(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):
450056106
1
Names of Reporting Persons
RTW Investments, 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
1,668,500.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
1,668,500.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
1,668,500.00
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)
5.2 %
12
Type of Reporting Person (See Instructions)
IA, PN
SCHEDULE 13G
CUSIP Number(s):
450056106
1
Names of Reporting Persons
Roderick Wong
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
1,668,500.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
1,668,500.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
1,668,500.00
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)
5.2 %
12
Type of Reporting Person (See Instructions)
HC, IN
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, CA, 94103.
Item 2.
(a)
Name of person filing:
This statement is filed by:
(i) RTW Investments, LP ("RTW Investments"), a Delaware limited partnership and the investment adviser to certain funds (the "RTW Funds"), with respect to shares of Common Stock, par value $0.001 per share (the "Shares") of iRhythm Holdings, Inc. (the "Company") directly held by the RTW Funds; and
(ii) Roderick Wong, M.D. ("Dr. Wong"), the Managing Partner and Chief Investment Officer of RTW Investments, with respect to the Shares directly held by the RTW Funds.
The foregoing persons are hereinafter sometimes collectively referred to as the "Reporting Persons."
The filing of this statement should not be construed as an admission that any of the foregoing persons or any Reporting Person is, for the purposes of Section 13 of the Securities Exchange Act of 1934, as amended, the beneficial owner of the Shares reported herein.
(b)
Address or principal business office or, if none, residence:
The address of the business office of each of the Reporting Persons is 40 10th Avenue, Floor 7, New York, New York 10014.
(c)
Citizenship:
RTW Investments is a Delaware limited partnership. Dr. Wong is a citizen of the United States.
(d)
Title of class of securities:
Common Stock, $0.001 par value
(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:
The information required by Item 4(a) is set forth in Rows 5 - 9 of the cover page for each of the Reporting Persons and is incorporated herein by reference. The percentages set forth in Row 11 of the cover pages are calculated based upon 32,316,760 Shares outstanding as of February 12, 2026 as reported in the Company's Annual Report on Form 10-K filed with the Securities and Exchange Commission on February 19, 2026.
(b)
Percent of class:
RTW Investments: 5.2%
Dr. Wong: 5.2%
(c)
Number of shares as to which the person has:
(i) Sole power to vote or to direct the vote:
RTW Investments: 0
Dr. Wong: 0
(ii) Shared power to vote or to direct the vote:
RTW Investments: 1,668,500 Shares
Dr. Wong: 1,668,500 Shares
(iii) Sole power to dispose or to direct the disposition of:
RTW Investments: 0
Dr. Wong: 0
(iv) Shared power to dispose or to direct the disposition of:
RTW Investments: 1,668,500 Shares
Dr. Wong: 1,668,500 Shares
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.
See Item 2. The RTW Funds have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, the Shares reported herein.
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.
