Who owns IRWD (IRWD)
Which tracked institutional funds hold IRWD, how they are positioned, and who is buying versus exiting — from SEC Form 13F-HR filings. See IRWD company fundamentals →
Ownership as of the 2026-Q1 13F filings. 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
The tracked-fund tape on IRWD is one-sided between 2025-Q4 and 2026-Q1: 56 added or opened and 19 trimmed or exited — on balance accumulating.
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
IRWD’s largest tracked holder by dollar value, ARMISTICE CAPITAL, LLC, sizes it at 1.7% of its own reported 13F book, while the median holder sizes it at 0.0% of theirs — a 1.7pp conviction gap — its largest holder concentrates the name more heavily than the typical one.
Book-share is each fund’s reported value in IRWD 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 2025-Q4 and 2026-Q1, across 226 tracked filers holding IRWD, 141 increased or opened the position and 86 reduced or closed it; over the same quarter, open-market insider Form 4 buying and selling roughly offset.
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 IRWD between the 2025-Q4 and 2026-Q1 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 15
- VANGUARD PORTFOLIO MANAGEMENT LLC$23M
- VANGUARD CAPITAL MANAGEMENT LLC$21M
- VANGUARD FIDUCIARY TRUST CO$3M
- Vanguard Global Advisers, LLC$2M
- WEDGE CAPITAL MANAGEMENT L L P/NC$2M
- Inspire Investing, LLC$2M
Full exits 5
- VANGUARD GROUP INC$47M
- TWO SIGMA ADVISERS, LP$11M
- DIADEMA PARTNERS LP$2M
- Exome Asset Management LLC$2M
- Persistent Asset Partners Ltd$613K
Largest adds
- BALYASNY ASSET MANAGEMENT L.P.$18M
- STATE STREET CORP$11M
- TWO SIGMA INVESTMENTS, LP$11M
- ARROWSTREET CAPITAL, LIMITED PARTNERSHIP$11M
- AQR CAPITAL MANAGEMENT LLC$10M
- DIMENSIONAL FUND ADVISORS LP$6M
Largest trims
- Sarissa Capital Management LP$21M
- BANK OF AMERICA CORP /DE/$8M
- JANE STREET GROUP, LLC$7M
- LAZARD ASSET MANAGEMENT LLC$2M
- ARMISTICE CAPITAL, LLC$1M
- BARCLAYS PLC$1M
Institutional holders
One row per tracked fund, largest reported value first. “% of value” is the fund’s share of this security’s tracked institutional value — not of shares outstanding. Rows marked stale are from an earlier filing than the security’s latest quarter — that fund is absent from the newest snapshot (position exited, or reported under a different name).
| Fund | Shares | Reported value | % of value | Quarter |
|---|---|---|---|---|
| ARMISTICE CAPITAL, LLC trimmed | 15,028,000 | $53M | 8.0% | 2026-Q1 |
| BlackRock, Inc. added | 13,362,930 | $47M | 7.1% | 2026-Q1 |
| Sarissa Capital Management LP trimmed | 9,188,635 | $32M | 4.9% | 2026-Q1 |
| BANK OF AMERICA CORP /DE/ trimmed | 8,682,907 | $30M | 4.6% | 2026-Q1 |
| RENAISSANCE TECHNOLOGIES LLC trimmed | 8,061,073 | $28M | 4.3% | 2026-Q1 |
| AQR CAPITAL MANAGEMENT LLC added | 7,475,676 | $26M | 4.0% | 2026-Q1 |
| STATE STREET CORP added | 7,456,944 | $26M | 4.0% | 2026-Q1 |
| VANGUARD PORTFOLIO MANAGEMENT LLC new | 6,682,037 | $23M | 3.6% | 2026-Q1 |
| ACADIAN ASSET MANAGEMENT LLC added | 6,577,272 | $23M | 3.5% | 2026-Q1 |
| VANGUARD CAPITAL MANAGEMENT LLC new | 6,097,454 | $21M | 3.2% | 2026-Q1 |
| TWO SIGMA INVESTMENTS, LP added | 5,848,276 | $21M | 3.1% | 2026-Q1 |
| BALYASNY ASSET MANAGEMENT L.P. added | 18,405,000 | $18M | 2.7% | 2026-Q1 |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC trimmed | 4,737,857 | $17M | 2.5% | 2026-Q1 |
| GEODE CAPITAL MANAGEMENT, LLC added | 4,543,522 | $16M | 2.4% | 2026-Q1 |
| MARSHALL WACE, LLP added | 4,525,064 | $16M | 2.4% | 2026-Q1 |
| JACOBS LEVY EQUITY MANAGEMENT, INC added | 3,632,477 | $13M | 1.9% | 2026-Q1 |
| ARROWSTREET CAPITAL, LIMITED PARTNERSHIP added | 3,397,242 | $12M | 1.8% | 2026-Q1 |
| FEDERATED HERMES, INC. added | 3,348,806 | $12M | 1.8% | 2026-Q1 |
| GOLDMAN SACHS GROUP INC added | 2,690,634 | $9M | 1.4% | 2026-Q1 |
| DIMENSIONAL FUND ADVISORS LP added | 2,082,055 | $7M | 1.1% | 2026-Q1 |
| Connor, Clark & Lunn Investment Management Ltd. trimmed | 1,835,424 | $6M | 1.0% | 2026-Q1 |
| Qube Research & Technologies Ltd trimmed | 1,590,081 | $6M | 0.8% | 2026-Q1 |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP added | 1,472,157 | $5M | 0.8% | 2026-Q1 |
| NORTHERN TRUST CORP added | 1,265,842 | $4M | 0.7% | 2026-Q1 |
| Hillsdale Investment Management Inc. added | 1,236,628 | $4M | 0.7% | 2026-Q1 |
| Pacer Advisors, Inc. added | 1,139,831 | $4M | 0.6% | 2026-Q1 |
| DEUTSCHE BANK AG\ added | 1,124,989 | $4M | 0.6% | 2026-Q1 |
| VANGUARD FIDUCIARY TRUST CO new | 988,630 | $3M | 0.5% | 2026-Q1 |
| UBS Group AG added | 933,225 | $3M | 0.5% | 2026-Q1 |
| MORGAN STANLEY added | 824,819 | $3M | 0.4% | 2026-Q1 |
| FMR LLC added | 790,386 | $3M | 0.4% | 2026-Q1 |
| RAYMOND JAMES FINANCIAL INC trimmed | 763,955 | $3M | 0.4% | 2026-Q1 |
| FRANKLIN RESOURCES INC added | 744,638 | $3M | 0.4% | 2026-Q1 |
| IEQ CAPITAL, LLC added | 742,723 | $3M | 0.4% | 2026-Q1 |
| SEI INVESTMENTS CO added | 742,548 | $3M | 0.4% | 2026-Q1 |
| VICTORY CAPITAL MANAGEMENT INC added | 713,187 | $3M | 0.4% | 2026-Q1 |
| GSA CAPITAL PARTNERS LLP added | 654,445 | $2M | 0.3% | 2026-Q1 |
| JANE STREET GROUP, LLC trimmed | 622,247 | $2M | 0.3% | 2026-Q1 |
| STATE OF WISCONSIN INVESTMENT BOARD added | 598,159 | $2M | 0.3% | 2026-Q1 |
| Vanguard Global Advisers, LLC new | 591,489 | $2M | 0.3% | 2026-Q1 |
| MACKENZIE FINANCIAL CORP added | 560,034 | $2M | 0.3% | 2026-Q1 |
| Integrated Quantitative Investments LLC added | 552,104 | $2M | 0.3% | 2026-Q1 |
| Invesco Ltd. added | 547,360 | $2M | 0.3% | 2026-Q1 |
| Man Group plc added | 540,864 | $2M | 0.3% | 2026-Q1 |
| WEDGE CAPITAL MANAGEMENT L L P/NC added | 540,492 | $2M | 0.3% | 2026-Q1 |
| Inspire Investing, LLC trimmed | 509,941 | $2M | 0.3% | 2026-Q1 |
| LOS ANGELES CAPITAL MANAGEMENT LLC trimmed | 509,247 | $2M | 0.3% | 2026-Q1 |
| Bank of New York Mellon Corp trimmed | 484,036 | $2M | 0.3% | 2026-Q1 |
| MILLENNIUM MANAGEMENT LLC trimmed | 457,114 | $2M | 0.2% | 2026-Q1 |
| WELLINGTON MANAGEMENT GROUP LLP trimmed | 453,515 | $2M | 0.2% | 2026-Q1 |
| PRUDENTIAL FINANCIAL INC added | 449,839 | $2M | 0.2% | 2026-Q1 |
| BRIDGEWAY CAPITAL MANAGEMENT, LLC trimmed | 440,493 | $2M | 0.2% | 2026-Q1 |
| Range Financial Group LLC added | 433,256 | $2M | 0.2% | 2026-Q1 |
| Amundi trimmed | 404,237 | $1M | 0.2% | 2026-Q1 |
| BNP PARIBAS ASSET MANAGEMENT Holding S.A. trimmed | 375,288 | $1M | 0.2% | 2026-Q1 |
| Cerity Partners LLC added | 368,370 | $1M | 0.2% | 2026-Q1 |
| CM Management, LLC new | 350,000 | $1M | 0.2% | 2026-Q1 |
| Robeco Institutional Asset Management B.V. | 342,998 | $1M | 0.2% | 2026-Q1 |
| LSV ASSET MANAGEMENT added | 308,271 | $1M | 0.2% | 2026-Q1 |
| Tidal Investments LLC added | 304,475 | $1M | 0.2% | 2026-Q1 |
| LAZARD ASSET MANAGEMENT LLC trimmed | 290,189 | $1M | 0.2% | 2026-Q1 |
| CWM, LLC added | 278,217 | $977K | 0.1% | 2026-Q1 |
| SEGALL BRYANT & HAMILL, LLC new | 278,201 | $976K | 0.1% | 2026-Q1 |
| Russell Investments Group, Ltd. trimmed | 261,789 | $915K | 0.1% | 2026-Q1 |
| GLOBEFLEX CAPITAL L P added | 259,809 | $912K | 0.1% | 2026-Q1 |
| Harvest Investment Services, LLC added | 241,881 | $849K | 0.1% | 2026-Q1 |
| WINTON GROUP Ltd added | 241,746 | $849K | 0.1% | 2026-Q1 |
| Nuveen, LLC added | 233,412 | $819K | 0.1% | 2026-Q1 |
| OMERS ADMINISTRATION Corp added | 226,310 | $794K | 0.1% | 2026-Q1 |
| Walleye Capital LLC trimmed | 225,136 | $790K | 0.1% | 2026-Q1 |
| Rafferty Asset Management, LLC added | 216,623 | $760K | 0.1% | 2026-Q1 |
| WEALTH ENHANCEMENT ADVISORY SERVICES, LLC added | 226,688 | $741K | 0.1% | 2026-Q1 |
| Mariner, LLC added | 207,779 | $729K | 0.1% | 2026-Q1 |
| MARTINGALE ASSET MANAGEMENT L P added | 204,991 | $720K | 0.1% | 2026-Q1 |
| RHUMBLINE ADVISERS trimmed | 192,934 | $677K | 0.1% | 2026-Q1 |
| Hennion & Walsh Asset Management, Inc. trimmed | 184,485 | $648K | 0.1% | 2026-Q1 |
| Vident Advisory, LLC added | 184,337 | $647K | 0.1% | 2026-Q1 |
| Creative Planning added | 177,520 | $623K | 0.1% | 2026-Q1 |
| KLP KAPITALFORVALTNING AS | 174,200 | $611K | 0.1% | 2026-Q1 |
| FIFTH THIRD BANCORP added | 165,094 | $579K | 0.1% | 2026-Q1 |
| ALLIANCEBERNSTEIN L.P. trimmed | 165,790 | $559K | 0.1% | 2026-Q1 |
| Legato Capital Management LLC added | 156,059 | $548K | 0.1% | 2026-Q1 |
| VOYA INVESTMENT MANAGEMENT LLC added | 145,819 | $512K | 0.1% | 2026-Q1 |
| CANADA PENSION PLAN INVESTMENT BOARD trimmed | 135,000 | $474K | 0.1% | 2026-Q1 |
| VANGUARD GROUP INC trimmed | 14,094,852 | $47M | 7.2% | 2025-Q4 stale |
| TWO SIGMA ADVISERS, LP trimmed | 3,140,100 | $11M | 1.6% | 2025-Q4 stale |
| BRAIDWELL LP added | 6,622,584 | $10M | 1.5% | 2025-Q1 stale |
| Kynam Capital Management, LP | 5,466,825 | $7M | 1.1% | 2025-Q3 stale |
| DIADEMA PARTNERS LP new | 683,611 | $2M | 0.3% | 2025-Q4 stale |
| Point72 Asset Management, L.P. added | 1,532,565 | $2M | 0.3% | 2025-Q1 stale |
| Exome Asset Management LLC new | 648,532 | $2M | 0.3% | 2025-Q4 stale |
| JUPITER ASSET MANAGEMENT LTD | 1,223,275 | $2M | 0.3% | 2025-Q1 stale |
| NORGES BANK trimmed | 394,266 | $2M | 0.2% | 2025-Q3 stale |
| Sio Capital Management, LLC added | 1,017,616 | $1M | 0.2% | 2025-Q1 stale |
| Voleon Capital Management LP added | 870,629 | $1M | 0.2% | 2025-Q1 stale |
| ExodusPoint Capital Management, LP added | 494,620 | $727K | 0.1% | 2025-Q1 stale |
| HIGHBRIDGE CAPITAL MANAGEMENT LLC new | 537,252 | $704K | 0.1% | 2025-Q3 stale |
| Persistent Asset Partners Ltd new | 182,046 | $613K | 0.1% | 2025-Q4 stale |
| AXA S.A. added | 332,810 | $489K | 0.1% | 2025-Q1 stale |
| PRELUDE CAPITAL MANAGEMENT, LLC added | 136,507 | $460K | 0.1% | 2025-Q4 stale |
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.