iRhythm Technologies, Inc. (IRTC) Ownership
IRTC ownership summary
as of October 18, 2026- Institutions
- 107.8% of shares outstanding
- Insiders
- 1.17% of shares outstanding
- Shares outstanding
- 33.0M
- Float
- 30.3M shares available to trade
- Short interest
- 9.29% 3.0M shares short
- Days to cover
- 5.63 short interest down 0.7% vs prior month
- Institutions 107.84%
- Insiders 1.17%
IRTC top institutional holders
20 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | BlackRock Inc | 9.06% | 3.0M | $324.4M | +244,162 (+8.9%) | June 30, 2026 |
| 2 | RTW INVESTMENTS, LLC | 6.62% | 2.2M | $237.2M | +514,131 (+30.8%) | June 30, 2026 |
| 3 | Vanguard Portfolio Management, LLC | 5.81% | 1.9M | $208.0M | +117,604 (+6.5%) | June 30, 2026 |
| 4 | Artisan Partners Limited Partnership | 5.04% | 1.7M | $180.4M | +209,400 (+14.4%) | June 30, 2026 |
| 5 | Vanguard Capital Management, LLC | 4.44% | 1.5M | $159.0M | +17,501 (+1.2%) | June 30, 2026 |
| 6 | Millennium Management LLC | 4.27% | 1.4M | $152.8M | −201,560 (−12.5%) | June 30, 2026 |
| 7 | FMR Inc | 3.62% | 1.2M | $129.5M | −169,937 (−12.5%) | June 30, 2026 |
| 8 | UBS Asset Mgmt Americas Inc | 2.87% | 945K | $102.6M | −102,935 (−9.8%) | June 30, 2026 |
| 9 | Geode Capital Management, LLC | 2.68% | 882K | $95.8M | +64,789 (+7.9%) | June 30, 2026 |
| 10 | Eventide Asset Management, LLC | 2.67% | 880K | $95.7M | +119,513 (+15.7%) | June 30, 2026 |
| 11 | BNP Paribas Investment Partners SA | 2.63% | 867K | $94.2M | +104,466 (+13.7%) | June 30, 2026 |
| 12 | State Street Corp | 2.60% | 857K | $93.1M | +68,215 (+8.7%) | June 30, 2026 |
| 13 | Holocene Advisors, LP | 2.38% | 784K | $85.1M | −465,022 (−37.2%) | June 30, 2026 |
| 14 | JPMorgan Chase & Co | 2.32% | 766K | $83.3M | +51,320 (+7.2%) | June 30, 2026 |
| 15 | Stephens Inv Mgmt Group LLC | 2.10% | 693K | $75.3M | +131,907 (+23.5%) | June 30, 2026 |
| 16 | Fuller & Thaler Asset Management Inc | 2.08% | 685K | $74.5M | +10,798 (+1.6%) | June 30, 2026 |
| 17 | BRAIDWELL LP | 1.98% | 654K | $71.1M | +44,070 (+7.2%) | June 30, 2026 |
| 18 | D. E. Shaw & Co LP | 1.91% | 630K | $68.4M | +75,420 (+13.6%) | June 30, 2026 |
| 19 | Manufacturers Life Insurance Co | 1.70% | 561K | $61.0M | +170,674 (+43.7%) | June 30, 2026 |
| 20 | Blair William & Co | 1.59% | 525K | $57.0M | −103,695 (−16.5%) | June 30, 2026 |
Value at the latest close. Change = shares bought or sold in the latest quarterly filing (13F). In the top 20, 15 holders added 1.9M shares and 5 cut 1.0M.
IRTC top mutual fund and ETF holders
20 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | Vanguard MStar Total Stk Mkt Idx Invest | 3.12% | 1.0M | $111.8M | −1,580 (−0.2%) | August 31, 2026 |
| 2 | iShares Russell 2000 ETF | 2.59% | 855K | $92.9M | −9,856 (−1.1%) | September 30, 2026 |
| 3 | Vanguard Small Cap Index | 2.21% | 728K | $79.1M | −15,940 (−2.1%) | September 30, 2026 |
| 4 | Eventide Gilead N | 1.77% | 582K | $63.3M | +118,220 (+25.5%) | June 30, 2026 |
| 5 | Vanguard Explorer Inv | 1.58% | 522K | $56.7M | +77,685 (+17.5%) | June 30, 2026 |
| 6 | FullerThaler Behavioral Sm-Cp Gr R6 | 1.31% | 432K | $47.0M | +37,800 (+9.6%) | March 31, 2026 |
| 7 | Artisan Mid Cap Investor | 1.30% | 428K | $46.5M | +49,724 (+13.1%) | September 30, 2026 |
| 8 | Vanguard MStar Small Cap Growth Indx Inv | 1.23% | 405K | $44.0M | −22,396 (−5.2%) | September 30, 2026 |
| 9 | Fidelity Small Cap Index | 1.10% | 362K | $39.3M | +2,893 (+0.8%) | July 31, 2026 |
| 10 | Harbor Small Cap Growth Instl | 1.01% | 332K | $36.1M | +190,167 (+133.8%) | September 30, 2026 |
| 11 | iShares Russell 2000 Growth ETF | 0.94% | 310K | $33.7M | −392 (−0.1%) | September 30, 2026 |
| 12 | Polar Capital Healthcare Opports Inc | 0.86% | 285K | $30.9M | — | August 31, 2026 |
| 13 | Fidelity Select Medical Tech and Devcs | 0.85% | 280K | $30.4M | −40,000 (−12.5%) | August 31, 2026 |
| 14 | Eventide Healthcare & Life Sciences I | 0.84% | 278K | $30.2M | — | June 30, 2026 |
| 15 | BNP Paribas Disrpt Tech Cl D | 0.79% | 260K | $28.2M | +58,445 (+29.1%) | August 31, 2026 |
| 16 | Bridge Builder Small/Mid Cap Growth | 0.75% | 248K | $27.0M | −250,682 (−50.3%) | September 30, 2026 |
| 17 | BNP Paribas Health Cr Innovtr Cl Cap | 0.70% | 230K | $25.0M | −42 (−0.0%) | August 31, 2026 |
| 18 | BNP Paribas US Small Cap ClassicC | 0.67% | 221K | $24.1M | +22,454 (+11.3%) | August 31, 2026 |
| 19 | JPMorgan Mid Cap Growth I | 0.66% | 216K | $23.5M | −100,429 (−31.7%) | August 31, 2026 |
| 20 | American Funds SMALLCAP World A | 0.63% | 207K | $22.5M | −119,226 (−36.6%) | September 30, 2026 |
Funds report holdings monthly or quarterly; dates differ by fund.
IRTC insider transactions
latest 20| Date | Name | Transaction | Price | Shares | Value |
|---|---|---|---|---|---|
| 2026-03-02 | Marc Wade Rosenbaum | Sell | $128.45 | 816 | $104,815 |
| 2026-03-02 | Chad Patterson | Sell | $128.44 | 4,444 | $570,787 |
| 2026-03-02 | Sumi Shrishrimal | Sell | $128.44 | 2,830 | $363,485 |
| 2026-03-02 | Patrick Michael Murphy | Sell | $128.44 | 4,357 | $559,613 |
| 2026-03-02 | Minang Turakhia | Sell | $128.45 | 4,027 | $517,268 |
| 2026-03-02 | Mervin Smith | Sell | $128.44 | 1,352 | $173,651 |
| 2026-02-25 | Chad Patterson | Sell | $135.42 | 8,967 | $1.2M |
| 2026-02-25 | Daniel G Wilson | Sell | $135.42 | 5,188 | $702,559 |
| 2026-02-25 | Marc Wade Rosenbaum | Sell | $135.42 | 4,797 | $649,610 |
| 2026-02-25 | Mervin Smith | Sell | $135.42 | 4,041 | $547,232 |
| 2026-02-25 | Minang Turakhia | Sell | $135.42 | 7,804 | $1.1M |
| 2026-02-25 | Patrick Michael Murphy | Sell | $135.42 | 7,805 | $1.1M |
| 2026-02-25 | Quentin S Blackford | Sell | $135.42 | 25,540 | $3.5M |
| 2026-02-25 | Sumi Shrishrimal | Sell | $135.42 | 6,217 | $841,906 |
| 2026-02-24 | Marc Wade Rosenbaum | Sell | $140.91 | 280 | $39,455 |
| 2026-02-24 | Mervin Smith | Sell | $140.91 | 732 | $103,146 |
| 2026-02-23 | Abhijit Y Talwalkar | Sell | $145.70 | 5,312 | $773,958 |
| 2025-12-02 | Chad Patterson | Sell | $184.83 | 280 | $51,752 |
| 2025-12-02 | Patrick Michael Murphy | Sell | $184.83 | 2,478 | $458,009 |
| 2025-11-03 | Quentin S Blackford | Sell | $182.94 | 14,059 | $2.6M |
Reported trades by company officers, directors and other filers (including disclosures by members of Congress where EODHD lists them). "—" where the filing gives no share count.
IRTC shares outstanding
Year-end shares outstanding, adjusted for splits.
Who owns IRTC
Institutional investors own 107.8% of iRhythm's shares and insiders 1.17%. The largest holder is BlackRock Inc with 9.06% of the shares (3.0M), as of June 30, 2026. Among the top 20 institutions, 15 added shares and 5 reduced their stake in the latest filings. Short interest is 9.29% of the float, or 5.63 days of average trading volume. The share count rose 2,412.2% since 2014.
Related: IRTC analyst forecast, IRTC key metrics. See the IRTC stock overview for the latest quote and news.
IRTC ownership FAQ
Who owns the most iRhythm stock?
The largest shareholders of iRhythm are BlackRock Inc (9.06%), RTW INVESTMENTS, LLC (6.62%), Vanguard Portfolio Management, LLC (5.81%), Artisan Partners Limited Partnership (5.04%), Vanguard Capital Management, LLC (4.44%).
What percentage of iRhythm is owned by institutions?
Institutions hold 107.8% of iRhythm's shares outstanding; insiders hold 1.17%.
Which funds own iRhythm?
The largest fund holders of iRhythm are Vanguard MStar Total Stk Mkt Idx Invest (3.12%), iShares Russell 2000 ETF (2.59%), Vanguard Small Cap Index (2.21%), Eventide Gilead N (1.77%), Vanguard Explorer Inv (1.58%).
What is iRhythm's short interest?
3.0M shares of iRhythm were sold short, 9.29% of the float; at the average daily volume it would take 5.63 days to cover.
Are insiders buying or selling iRhythm?
Of the latest 20 reported insider transactions in iRhythm (since November 3, 2025), 0 were purchases and 20 were sales.
How many shares of iRhythm are outstanding?
iRhythm has 33.0M shares outstanding, of which 30.3M are in the public float.