Ironwood Pharmaceuticals Inc
Ownership
Ownership Structure
Who owns Ironwood Pharmaceuticals Inc (IRWD)? This page shows the largest institutions and funds, the ownership structure and the latest insider transactions. 82.8% of the shares are freely tradable; institutional investors hold 98.9%.
Largest Shareholders
Institutions
| Name | Stake (%) | Shares | Change (%) | Date |
|---|---|---|---|---|
| Armistice Capital, LLC | 9.09 | 15,028,000 | -6.2 | 03/31/2026 |
| BlackRock Inc | 8.09 | 13,362,930 | +4.5 | 03/31/2026 |
| Sarissa Capital Management LP | 5.56 | 9,188,635 | +0.0 | 06/30/2026 |
| Bank of America Corp | 5.25 | 8,682,907 | -24.6 | 03/31/2026 |
| Renaissance Technologies Corp | 4.88 | 8,061,073 | -1.8 | 03/31/2026 |
| AQR Capital Management LLC | 4.56 | 7,535,080 | +59.5 | 03/31/2026 |
| State Street Corp | 4.51 | 7,456,944 | +69.0 | 03/31/2026 |
| Vanguard Portfolio Management, LLC | 4.04 | 6,682,037 | +0.0 | 03/31/2026 |
| Acadian Asset Management LLC | 3.98 | 6,577,272 | +2,378.7 | 03/31/2026 |
| Vanguard Capital Management, LLC | 3.69 | 6,097,454 | +0.0 | 03/31/2026 |
Largest reported positions according to regulatory filings; stake as a percentage of shares outstanding, change versus the previous filing. Source: fundamentals data.
Insider holdings
| Person | Role | Shares | Value | As of | Type |
|---|---|---|---|---|---|
| Silver Ronald | PFO & PAO | 313,680 | 1,317,456 $ | Jul 7, 2026 | direct |
| Silber Jeffrey | SVP, CMO, Head-Res&Drug | 137,036 | 575,551 $ | Jul 20, 2026 | direct |
Holdings as of each person's most recent SEC Form 4 filing — excluding options and RSUs, which are not shares yet. Holdings may have changed between two filings.
Insiders
Insider Transactions
| Date | Person | Role | Type | Shares | Price | Value |
|---|---|---|---|---|---|---|
| Jul 20, 2026 | Silber Jeffrey | SVP, CMO, Head-Res&Drug | Other | 137,036 | 0.00 | – |
| Jul 7, 2026 | Silver Ronald | PFO & PAO | Sell | 127,890 | 4.52 | 578,063 |
Reportable transactions by officers and major shareholders from SEC Form 4 filings. "Other" includes things like stock grants and option exercises without a buy/sell character. View all insider transactions →
Data as of: September 17, 2026 · Source: fundamental data & SEC filings (annual and quarterly reports, 10-K/10-Q)
Note: pure fact-based analysis, not investment advice and not a solicitation to buy or sell. All figures without guarantee.