Who owns Ironwood Pharmaceuticals (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-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
48 tracked funds added or opened IRWD while 26 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
IRWD’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 IRWD more heavily than its largest holder by dollar value does.
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 2026-Q1 and 2026-Q2, across 201 tracked filers holding IRWD, 95 increased or opened the position and 125 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 IRWD 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 1
- CWA Asset Management Group, LLC$1M
Full exits 12
- ACADIAN ASSET MANAGEMENT LLC$23M
- BALYASNY ASSET MANAGEMENT L.P.$18M
- Pacer Advisors, Inc.$4M
- GSA CAPITAL PARTNERS LLP$2M
- MILLENNIUM MANAGEMENT LLC$2M
- Amundi$1M
Largest adds
- BlackRock, Inc.$28M
- STATE STREET CORP$11M
- MACKENZIE FINANCIAL CORP$8M
- Sarissa Capital Management LP$6M
- VANGUARD CAPITAL MANAGEMENT LLC$6M
- BANK OF AMERICA CORP /DE/$6M
Largest trims
- SUSQUEHANNA INTERNATIONAL GROUP, LLP$5M
- Qube Research & Technologies Ltd$4M
- CHARLES SCHWAB INVESTMENT MANAGEMENT INC$3M
- JANE STREET GROUP, LLC$2M
- UBS Group AG$2M
- Integrated Quantitative Investments LLC$2M
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 |
|---|---|---|---|---|
| BlackRock, Inc. added | 17,788,557 | $75M | 11.8% | 2026-Q2 |
| ARMISTICE CAPITAL, LLC trimmed | 13,932,000 | $59M | 9.2% | 2026-Q2 |
| Sarissa Capital Management LP | 9,188,635 | $39M | 6.1% | 2026-Q2 |
| STATE STREET CORP added | 8,809,601 | $37M | 5.8% | 2026-Q2 |
| BANK OF AMERICA CORP /DE/ added | 8,683,803 | $37M | 5.8% | 2026-Q2 |
| RENAISSANCE TECHNOLOGIES LLC trimmed | 7,993,226 | $34M | 5.3% | 2026-Q2 |
| VANGUARD CAPITAL MANAGEMENT LLC added | 6,608,508 | $28M | 4.4% | 2026-Q2 |
| AQR CAPITAL MANAGEMENT LLC trimmed | 6,465,921 | $27M | 4.3% | 2026-Q2 |
| VANGUARD PORTFOLIO MANAGEMENT LLC trimmed | 5,513,355 | $23M | 3.7% | 2026-Q2 |
| GEODE CAPITAL MANAGEMENT, LLC added | 4,831,657 | $20M | 3.2% | 2026-Q2 |
| TWO SIGMA INVESTMENTS, LP trimmed | 4,556,089 | $19M | 3.0% | 2026-Q2 |
| MARSHALL WACE, LLP trimmed | 4,290,093 | $18M | 2.8% | 2026-Q2 |
| JACOBS LEVY EQUITY MANAGEMENT, INC added | 4,065,964 | $17M | 2.7% | 2026-Q2 |
| GOLDMAN SACHS GROUP INC added | 3,313,808 | $14M | 2.2% | 2026-Q2 |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC trimmed | 3,302,242 | $14M | 2.2% | 2026-Q2 |
| FEDERATED HERMES, INC. trimmed | 3,231,238 | $14M | 2.1% | 2026-Q2 |
| ARROWSTREET CAPITAL, LIMITED PARTNERSHIP trimmed | 3,017,089 | $13M | 2.0% | 2026-Q2 |
| DIMENSIONAL FUND ADVISORS LP added | 2,522,891 | $11M | 1.7% | 2026-Q2 |
| MACKENZIE FINANCIAL CORP added | 2,367,493 | $10M | 1.6% | 2026-Q2 |
| MORGAN STANLEY added | 1,859,914 | $8M | 1.2% | 2026-Q2 |
| Connor, Clark & Lunn Investment Management Ltd. trimmed | 1,811,714 | $8M | 1.2% | 2026-Q2 |
| NORTHERN TRUST CORP added | 1,373,974 | $6M | 0.9% | 2026-Q2 |
| Hillsdale Investment Management Inc. added | 1,250,428 | $5M | 0.8% | 2026-Q2 |
| WELLS FARGO & COMPANY/MN added | 1,206,198 | $5M | 0.8% | 2026-Q2 |
| DEUTSCHE BANK AG\ added | 1,158,138 | $5M | 0.8% | 2026-Q2 |
| VANGUARD FIDUCIARY TRUST CO added | 1,040,335 | $4M | 0.7% | 2026-Q2 |
| FRANKLIN RESOURCES INC added | 1,006,979 | $4M | 0.7% | 2026-Q2 |
| FMR LLC added | 909,488 | $4M | 0.6% | 2026-Q2 |
| STATE OF WISCONSIN INVESTMENT BOARD added | 778,515 | $3M | 0.5% | 2026-Q2 |
| RAYMOND JAMES FINANCIAL INC trimmed | 725,085 | $3M | 0.5% | 2026-Q2 |
| VICTORY CAPITAL MANAGEMENT INC trimmed | 658,457 | $3M | 0.4% | 2026-Q2 |
| Inspire Investing, LLC added | 630,072 | $3M | 0.4% | 2026-Q2 |
| IEQ CAPITAL, LLC trimmed | 561,588 | $2M | 0.4% | 2026-Q2 |
| Vanguard Global Advisers, LLC trimmed | 561,038 | $2M | 0.4% | 2026-Q2 |
| PRUDENTIAL FINANCIAL INC added | 537,199 | $2M | 0.4% | 2026-Q2 |
| Bank of New York Mellon Corp added | 508,880 | $2M | 0.3% | 2026-Q2 |
| CITADEL ADVISORS LLC added | 502,403 | $2M | 0.3% | 2026-Q2 |
| VOYA INVESTMENT MANAGEMENT LLC added | 484,450 | $2M | 0.3% | 2026-Q2 |
| WELLINGTON MANAGEMENT GROUP LLP added | 468,821 | $2M | 0.3% | 2026-Q2 |
| SEI INVESTMENTS CO trimmed | 459,417 | $2M | 0.3% | 2026-Q2 |
| O'SHAUGHNESSY ASSET MANAGEMENT, LLC added | 438,911 | $2M | 0.3% | 2026-Q2 |
| WEDGE CAPITAL MANAGEMENT L L P/NC trimmed | 435,650 | $2M | 0.3% | 2026-Q2 |
| SEGALL BRYANT & HAMILL, LLC added | 408,064 | $2M | 0.3% | 2026-Q2 |
| Invesco Ltd. trimmed | 403,209 | $2M | 0.3% | 2026-Q2 |
| Man Group plc trimmed | 392,117 | $2M | 0.3% | 2026-Q2 |
| BRIDGEWAY CAPITAL MANAGEMENT, LLC trimmed | 389,793 | $2M | 0.3% | 2026-Q2 |
| UBS Group AG trimmed | 389,529 | $2M | 0.3% | 2026-Q2 |
| BNP PARIBAS ASSET MANAGEMENT Holding S.A. | 375,288 | $2M | 0.2% | 2026-Q2 |
| RITHOLTZ WEALTH MANAGEMENT added | 360,094 | $2M | 0.2% | 2026-Q2 |
| Nuveen, LLC added | 355,372 | $1M | 0.2% | 2026-Q2 |
| CM Management, LLC | 350,000 | $1M | 0.2% | 2026-Q2 |
| Qube Research & Technologies Ltd trimmed | 347,985 | $1M | 0.2% | 2026-Q2 |
| Robeco Institutional Asset Management B.V. | 342,998 | $1M | 0.2% | 2026-Q2 |
| LOS ANGELES CAPITAL MANAGEMENT LLC trimmed | 342,293 | $1M | 0.2% | 2026-Q2 |
| Virtus Investment Advisers, LLC added | 318,598 | $1M | 0.2% | 2026-Q2 |
| CWA Asset Management Group, LLC new | 290,366 | $1M | 0.2% | 2026-Q2 |
| GLOBEFLEX CAPITAL L P | 259,809 | $1M | 0.2% | 2026-Q2 |
| CITIGROUP INC added | 226,824 | $955K | 0.2% | 2026-Q2 |
| Russell Investments Group, Ltd. trimmed | 224,821 | $946K | 0.1% | 2026-Q2 |
| WEALTH ENHANCEMENT ADVISORY SERVICES, LLC trimmed | 219,445 | $913K | 0.1% | 2026-Q2 |
| JPMORGAN CHASE & CO added | 212,575 | $914K | 0.1% | 2026-Q2 |
| Cerity Partners LLC trimmed | 208,019 | $876K | 0.1% | 2026-Q2 |
| RHUMBLINE ADVISERS added | 205,095 | $863K | 0.1% | 2026-Q2 |
| MARTINGALE ASSET MANAGEMENT L P | 204,991 | $863K | 0.1% | 2026-Q2 |
| EVOLVE PRIVATE WEALTH, LLC added | 186,864 | $787K | 0.1% | 2026-Q2 |
| Vident Advisory, LLC trimmed | 180,929 | $762K | 0.1% | 2026-Q2 |
| Creative Planning trimmed | 177,030 | $745K | 0.1% | 2026-Q2 |
| KLP KAPITALFORVALTNING AS | 174,200 | $733K | 0.1% | 2026-Q2 |
| Mariner, LLC trimmed | 168,472 | $709K | 0.1% | 2026-Q2 |
| ALLIANCEBERNSTEIN L.P. | 165,790 | $582K | 0.1% | 2026-Q2 |
| OMERS ADMINISTRATION Corp trimmed | 159,010 | $669K | 0.1% | 2026-Q2 |
| Rafferty Asset Management, LLC trimmed | 152,878 | $644K | 0.1% | 2026-Q2 |
| Quantinno Capital Management LP added | 150,604 | $634K | 0.1% | 2026-Q2 |
| FIFTH THIRD BANCORP trimmed | 132,748 | $559K | 0.1% | 2026-Q2 |
| CANADA PENSION PLAN INVESTMENT BOARD trimmed | 130,900 | $551K | 0.1% | 2026-Q2 |
| JANE STREET GROUP, LLC trimmed | 129,700 | $546K | 0.1% | 2026-Q2 |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP trimmed | 129,237 | $544K | 0.1% | 2026-Q2 |
| PRICE T ROWE ASSOCIATES INC /MD/ added | 128,772 | $543K | 0.1% | 2026-Q2 |
| Arax Advisory Partners added | 126,966 | $535K | 0.1% | 2026-Q2 |
| MERCER GLOBAL ADVISORS INC /ADV added | 126,160 | $531K | 0.1% | 2026-Q2 |
| HSBC HOLDINGS PLC added | 126,100 | $542K | 0.1% | 2026-Q2 |
| D. E. Shaw & Co., Inc. added | 122,907 | $517K | 0.1% | 2026-Q2 |
| Optimist Retirement Group LLC added | 102,054 | $430K | 0.1% | 2026-Q2 |
| State of Wyoming trimmed | 101,781 | $428K | 0.1% | 2026-Q2 |
| Cercano Management LLC | 101,378 | $427K | 0.1% | 2026-Q2 |
| BARCLAYS PLC added | 100,123 | $422K | 0.1% | 2026-Q2 |
| AMERIPRISE FINANCIAL INC added | 99,526 | $419K | 0.1% | 2026-Q2 |
| Engineers Gate Manager LP added | 98,052 | $413K | 0.1% | 2026-Q2 |
| MetLife Investment Management, LLC added | 96,208 | $405K | 0.1% | 2026-Q2 |
| Integrated Quantitative Investments LLC trimmed | 93,689 | $394K | 0.1% | 2026-Q2 |
| MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd. added | 93,191 | $394K | 0.1% | 2026-Q2 |
| FULLER & THALER ASSET MANAGEMENT, INC. trimmed | 90,321 | $380K | 0.1% | 2026-Q2 |
| WINTON GROUP Ltd trimmed | 84,156 | $354K | 0.1% | 2026-Q2 |
| Allspring Global Investments Holdings, LLC added | 82,315 | $339K | 0.1% | 2026-Q2 |
| PROFUND ADVISORS LLC trimmed | 77,754 | $327K | 0.1% | 2026-Q2 |
| SmartHarvest Portfolios, LLC | 75,462 | $318K | 0.1% | 2026-Q2 |
| Pallas Capital Advisors LLC trimmed | 73,996 | $312K | 0.0% | 2026-Q2 |
| CAPTRUST FINANCIAL ADVISORS trimmed | 71,706 | $302K | 0.0% | 2026-Q2 |
| Squarepoint Ops LLC added | 66,899 | $282K | 0.0% | 2026-Q2 |
| Vanguard Personalized Indexing Management, LLC trimmed | 64,187 | $270K | 0.0% | 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.