Who owns iRhythm Technologies (IRTC)
Which tracked institutional funds hold IRTC, how they are positioned, and who is buying versus exiting — from SEC Form 13F-HR filings. See IRTC company fundamentals →
Ownership as of the 2026-Q2 13F filings (latest filed 2026-09-22). 13F is disclosed up to 45 days after quarter-end, so the most recent quarter fills in over the following weeks.
How the tape is positioned
79 tracked funds added or opened IRTC while 70 trimmed or exited it between 2026-Q1 and 2026-Q2 — the tape is split. When large holders disagree on a name, the funds moving first are sometimes ahead of the story.
A prompt to read the filings, not a verdict. 13F is a quarter-end snapshot disclosed up to 45 days late; a fund adds or exits for mandate, benchmark, and timing reasons that have nothing to do with a view on the stock. This is a starting question, not a signal to trade.
Conviction spread
IRTC’s largest tracked holder by dollar value, BlackRock, Inc., sizes it at 0.0% of its own reported 13F book, while the median holder sizes it at 0.0% of theirs — a 0.0pp gap the other way — the median holder sizes IRTC more heavily than its largest holder by dollar value does.
Book-share is each fund’s reported value in IRTC divided by its whole reported 13F book, so it is comparable across funds of different sizes and is unaffected by stock splits. A higher share means a fund has committed more of its book to the name — a starting question about conviction, not a verdict or a signal to trade.
Institutional & insider positioning
Between 2026-Q1 and 2026-Q2, across 290 tracked filers holding IRTC, 157 increased or opened the position and 152 reduced or closed it; over the same quarter, open-market insider Form 4s were net sales.
This fuses two public signals for the same quarter — how tracked institutions changed their positions and whether insiders bought or sold in the open market. It describes what was filed; it is a starting question, not a verdict or a signal to trade.
New buyers & exits
Funds opening or closing a position in IRTC between the 2026-Q1 and 2026-Q2 13F filings, and the largest changes among funds holding it in both. New buyers and exits are counted on fund presence (split-invariant); adds and trims are measured on reported value.
New buyers 14
- WESTFIELD CAPITAL MANAGEMENT CO LP$34M
- NORGES BANK$18M
- USS Investment Management Ltd$13M
- Champlain Investment Partners, LLC$12M
- Integral Health Asset Management, LLC$11M
- PFM Health Sciences, LP$8M
Full exits 21
- MACKENZIE FINANCIAL CORP$44M
- M&G PLC$10M
- C WorldWide Group Holding A/S$9M
- Thrivent Financial for Lutherans$9M
- TWO SIGMA INVESTMENTS, LP$6M
- Amundi$6M
Largest adds
- BlackRock, Inc.$203M
- RTW INVESTMENTS, LP$63M
- Artisan Partners Limited Partnership$26M
- SCHRODER INVESTMENT MANAGEMENT GROUP$25M
- MANUFACTURERS LIFE INSURANCE COMPANY, THE$21M
- JANE STREET GROUP, LLC$19M
Largest trims
- Holocene Advisors, LP$54M
- Point72 Asset Management, L.P.$38M
- Assenagon Asset Management S.A.$29M
- Invesco Ltd.$29M
- BALYASNY ASSET MANAGEMENT L.P.$26M
- MILLENNIUM MANAGEMENT LLC$22M
Institutional holders
One row per tracked fund, most shares held first (every row is from one quarter; reported value breaks ties). “% of value” is the fund’s share of this security’s tracked institutional value — not of shares outstanding.
| Fund | Shares | Reported value | % of value | Quarter |
|---|---|---|---|---|
| TUDOR INVESTMENT CORP ET AL added | 21,750,000 | $24M | 0.6% | 2026-Q2 |
| BlackRock, Inc. added | 2,985,667 | $355M | 8.6% | 2026-Q2 |
| RTW INVESTMENTS, LP added | 2,182,631 | $260M | 6.3% | 2026-Q2 |
| VANGUARD PORTFOLIO MANAGEMENT LLC added | 1,913,976 | $228M | 5.5% | 2026-Q2 |
| Artisan Partners Limited Partnership added | 1,660,307 | $197M | 4.8% | 2026-Q2 |
| VANGUARD CAPITAL MANAGEMENT LLC added | 1,463,211 | $174M | 4.2% | 2026-Q2 |
| MILLENNIUM MANAGEMENT LLC trimmed | 1,406,454 | $167M | 4.1% | 2026-Q2 |
| FMR LLC trimmed | 1,191,982 | $142M | 3.4% | 2026-Q2 |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC trimmed | 944,517 | $112M | 2.7% | 2026-Q2 |
| GEODE CAPITAL MANAGEMENT, LLC added | 881,899 | $105M | 2.5% | 2026-Q2 |
| EVENTIDE ASSET MANAGEMENT, LLC added | 880,338 | $105M | 2.5% | 2026-Q2 |
| BNP PARIBAS ASSET MANAGEMENT Holding S.A. added | 866,528 | $103M | 2.5% | 2026-Q2 |
| STATE STREET CORP added | 856,517 | $102M | 2.5% | 2026-Q2 |
| Holocene Advisors, LP trimmed | 783,636 | $93M | 2.3% | 2026-Q2 |
| JPMORGAN CHASE & CO added | 766,216 | $91M | 2.2% | 2026-Q2 |
| Stephens Investment Management Group LLC added | 693,437 | $82M | 2.0% | 2026-Q2 |
| FULLER & THALER ASSET MANAGEMENT, INC. added | 685,496 | $82M | 2.0% | 2026-Q2 |
| BRAIDWELL LP added | 654,262 | $78M | 1.9% | 2026-Q2 |
| D. E. Shaw & Co., Inc. added | 629,686 | $75M | 1.8% | 2026-Q2 |
| MANUFACTURERS LIFE INSURANCE COMPANY, THE added | 561,251 | $67M | 1.6% | 2026-Q2 |
| BLAIR WILLIAM & CO/IL trimmed | 524,690 | $62M | 1.5% | 2026-Q2 |
| BANK OF AMERICA CORP /DE/ added | 465,719 | $55M | 1.3% | 2026-Q2 |
| Polar Capital Holdings Plc added | 458,089 | $54M | 1.3% | 2026-Q2 |
| ARROWSTREET CAPITAL, LIMITED PARTNERSHIP trimmed | 450,865 | $54M | 1.3% | 2026-Q2 |
| SCHRODER INVESTMENT MANAGEMENT GROUP added | 448,259 | $53M | 1.3% | 2026-Q2 |
| GOLDMAN SACHS GROUP INC added | 362,346 | $43M | 1.0% | 2026-Q2 |
| LOOMIS SAYLES & CO L P trimmed | 347,959 | $41M | 1.0% | 2026-Q2 |
| Capital Research Global Investors trimmed | 335,209 | $40M | 1.0% | 2026-Q2 |
| NORTHERN TRUST CORP added | 307,995 | $37M | 0.9% | 2026-Q2 |
| Allspring Global Investments Holdings, LLC trimmed | 300,057 | $37M | 0.9% | 2026-Q2 |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC added | 298,301 | $35M | 0.9% | 2026-Q2 |
| AMERIPRISE FINANCIAL INC added | 292,513 | $35M | 0.8% | 2026-Q2 |
| WESTFIELD CAPITAL MANAGEMENT CO LP trimmed | 288,924 | $34M | 0.8% | 2026-Q2 |
| JANE STREET GROUP, LLC added | 275,262 | $33M | 0.8% | 2026-Q2 |
| Point72 Asset Management, L.P. trimmed | 273,162 | $32M | 0.8% | 2026-Q2 |
| Qube Research & Technologies Ltd added | 271,624 | $32M | 0.8% | 2026-Q2 |
| Rock Springs Capital Management LP added | 269,650 | $32M | 0.8% | 2026-Q2 |
| CITIGROUP INC added | 249,404 | $30M | 0.7% | 2026-Q2 |
| DEUTSCHE BANK AG\ added | 238,193 | $28M | 0.7% | 2026-Q2 |
| VANGUARD FIDUCIARY TRUST CO added | 235,963 | $28M | 0.7% | 2026-Q2 |
| PERCEPTIVE ADVISORS LLC added | 223,766 | $27M | 0.6% | 2026-Q2 |
| FRED ALGER MANAGEMENT, LLC trimmed | 220,789 | $26M | 0.6% | 2026-Q2 |
| OBERWEIS ASSET MANAGEMENT INC/ added | 202,004 | $24M | 0.6% | 2026-Q2 |
| Ophir Asset Management Pty Ltd trimmed | 201,491 | $24M | 0.6% | 2026-Q2 |
| BARCLAYS PLC added | 191,798 | $23M | 0.6% | 2026-Q2 |
| NEXT CENTURY GROWTH INVESTORS LLC added | 187,064 | $22M | 0.5% | 2026-Q2 |
| BAMCO INC /NY/ trimmed | 181,430 | $22M | 0.5% | 2026-Q2 |
| SEI INVESTMENTS CO trimmed | 178,765 | $21M | 0.5% | 2026-Q2 |
| First Light Asset Management, LLC trimmed | 167,092 | $20M | 0.5% | 2026-Q2 |
| MASSACHUSETTS FINANCIAL SERVICES CO /MA/ trimmed | 165,998 | $20M | 0.5% | 2026-Q2 |
| Prosight Management, LP added | 165,500 | $20M | 0.5% | 2026-Q2 |
| Schonfeld Strategic Advisors LLC added | 152,062 | $18M | 0.4% | 2026-Q2 |
| NORGES BANK added | 148,072 | $18M | 0.4% | 2026-Q2 |
| MORGAN STANLEY trimmed | 147,998 | $18M | 0.4% | 2026-Q2 |
| TimesSquare Capital Management, LLC added | 137,311 | $16M | 0.4% | 2026-Q2 |
| RAYMOND JAMES FINANCIAL INC trimmed | 135,265 | $16M | 0.4% | 2026-Q2 |
| FRONTIER CAPITAL MANAGEMENT CO LLC added | 132,475 | $16M | 0.4% | 2026-Q2 |
| Bank of New York Mellon Corp added | 118,768 | $14M | 0.3% | 2026-Q2 |
| Nuveen, LLC added | 113,918 | $14M | 0.3% | 2026-Q2 |
| SEGALL BRYANT & HAMILL, LLC added | 107,467 | $13M | 0.3% | 2026-Q2 |
| WCM INVESTMENT MANAGEMENT, LLC trimmed | 107,000 | $13M | 0.3% | 2026-Q2 |
| USS Investment Management Ltd new | 106,957 | $13M | 0.3% | 2026-Q2 |
| Champlain Investment Partners, LLC trimmed | 97,015 | $12M | 0.3% | 2026-Q2 |
| Trexquant Investment LP trimmed | 96,268 | $11M | 0.3% | 2026-Q2 |
| CITADEL ADVISORS LLC trimmed | 95,931 | $11M | 0.3% | 2026-Q2 |
| FEDERATED HERMES, INC. trimmed | 95,871 | $11M | 0.3% | 2026-Q2 |
| NEW YORK STATE COMMON RETIREMENT FUND trimmed | 92,993 | $11M | 0.3% | 2026-Q2 |
| Integral Health Asset Management, LLC trimmed | 90,000 | $11M | 0.3% | 2026-Q2 |
| WELLINGTON MANAGEMENT GROUP LLP trimmed | 88,257 | $10M | 0.3% | 2026-Q2 |
| SILVERCREST ASSET MANAGEMENT GROUP LLC added | 85,830 | $10M | 0.2% | 2026-Q2 |
| Granahan Investment Management, LLC trimmed | 83,903 | $10M | 0.2% | 2026-Q2 |
| UBS Group AG trimmed | 77,665 | $9M | 0.2% | 2026-Q2 |
| PEREGRINE CAPITAL MANAGEMENT LLC added | 75,724 | $9M | 0.2% | 2026-Q2 |
| Squarepoint Ops LLC added | 71,862 | $9M | 0.2% | 2026-Q2 |
| JENNISON ASSOCIATES LLC trimmed | 67,924 | $8M | 0.2% | 2026-Q2 |
| Parkman Healthcare Partners LLC added | 67,267 | $8M | 0.2% | 2026-Q2 |
| Legal & General Group Plc added | 65,304 | $8M | 0.2% | 2026-Q2 |
| PFM Health Sciences, LP added | 65,196 | $8M | 0.2% | 2026-Q2 |
| Swiss National Bank added | 64,800 | $8M | 0.2% | 2026-Q2 |
| NEUBERGER BERMAN GROUP LLC added | 63,343 | $8M | 0.2% | 2026-Q2 |
| PRINCIPAL FINANCIAL GROUP INC added | 59,733 | $7M | 0.2% | 2026-Q2 |
| Verition Fund Management LLC added | 55,987 | $7M | 0.2% | 2026-Q2 |
| Atle Fund Management AB added | 54,102 | $6M | 0.2% | 2026-Q2 |
| Susquehanna Portfolio Strategies, LLC trimmed | 49,120 | $6M | 0.1% | 2026-Q2 |
| CANADA PENSION PLAN INVESTMENT BOARD trimmed | 48,700 | $6M | 0.1% | 2026-Q2 |
| WELLS FARGO & COMPANY/MN added | 47,903 | $6M | 0.1% | 2026-Q2 |
| STATE OF WISCONSIN INVESTMENT BOARD trimmed | 44,699 | $5M | 0.1% | 2026-Q2 |
| PRICE T ROWE ASSOCIATES INC /MD/ added | 44,239 | $5M | 0.1% | 2026-Q2 |
| CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM added | 44,067 | $5M | 0.1% | 2026-Q2 |
| Man Group plc trimmed | 43,362 | $5M | 0.1% | 2026-Q2 |
| ALLIANCEBERNSTEIN L.P. added | 42,595 | $5M | 0.1% | 2026-Q2 |
| Connor, Clark & Lunn Investment Management Ltd. trimmed | 42,314 | $5M | 0.1% | 2026-Q2 |
| RHUMBLINE ADVISERS added | 42,028 | $5M | 0.1% | 2026-Q2 |
| RENAISSANCE TECHNOLOGIES LLC trimmed | 38,500 | $5M | 0.1% | 2026-Q2 |
| SIRIOS CAPITAL MANAGEMENT L P trimmed | 34,455 | $4M | 0.1% | 2026-Q2 |
| Engineers Gate Manager LP trimmed | 30,418 | $4M | 0.1% | 2026-Q2 |
| VANGUARD ASSET MANAGEMENT, Ltd added | 30,320 | $4M | 0.1% | 2026-Q2 |
| EFG International AG trimmed | 28,913 | $3M | 0.1% | 2026-Q2 |
| SECTORAL ASSET MANAGEMENT INC new | 26,070 | $3M | 0.1% | 2026-Q2 |
| MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd. added | 25,532 | $3M | 0.1% | 2026-Q2 |
Ownership over time
Tracked institutional holder count and total shares held by filing quarter (independent scales). The curated-era tail and any mid-ingest latest quarter are handled honestly — a partial quarter is not drawn as a collapse.
Reading this table
Funds hold the same stock for different reasons — an index fund “holds” almost everything, an active manager sizes a name to a mandate and a benchmark, and each fund entered at its own price and time. Because 13F is filed up to 45 days after quarter-end, every row is a backward-looking snapshot; a manager may have traded since. Share-class siblings (a company’s A and C shares) are rolled up to one line so a dual-class name is never double-counted. Compare like-for-like. A large holder is not an endorsement, and a fund exiting is not a warning — this is a starting question, not a verdict.
About 13F filings
A Form 13F is a quarterly disclosure that institutional investment managers with over $100 million in US-listed equities must file with the SEC. In plain English: it is a snapshot of the long stock positions a fund held at the end of a quarter. It covers long US-listed equities only — not short positions, options, cash, or private holdings — and the funds shown are the large sample we track, not the complete 13F universe.