Ironwood Pharmaceuticals
IRWD · NASDAQ
$3.63+$0.07 (+1.97%)TodayMarket closed ·
Prev close $3.56
Who owns IRWD
Largest institutional holders, from their latest 13F filings
The 10 largest institutions hold 51.2% of IRWD’s shares.
- Armistice Capital LLC8.5%
- BlackRock Institutional Trust Company, N.A.8.4%
- Sarissa Capital Management, L.P.5.6%
- State Street Investment Management (US)5.4%
- Next 6 largest institutions23.4%
- All other shareholders48.8%
| Holder | Shares | % of shares |
|---|---|---|
| Armistice Capital LLC | 13.93M | 8.46% |
| BlackRock Institutional Trust Company, N.A. | 13.89M | 8.44% |
| Sarissa Capital Management, L.P. | 9.19M | 5.58% |
| State Street Investment Management (US) | 8.81M | 5.35% |
| Renaissance Technologies LLC | 7.99M | 4.86% |
| Vanguard Capital Management, LLC | 6.61M | 4.01% |
| AQR Capital Management, LLC | 6.47M | 3.93% |
| Bank of America Private Bank | 6.05M | 3.67% |
| Acadian Asset Management LLC | 5.85M | 3.56% |
| Vanguard Portfolio Management, LLC | 5.51M | 3.35% |
Largest mutual fund holders
| Holder | Shares | % of shares |
|---|---|---|
| State Street SPDR S&P Biotech ETF | 5.80M | 3.53% |
| Vanguard Total Stock Market Index Fund | 4.78M | 2.90% |
| iShares Russell 2000 ETF | 4.24M | 2.58% |
| Fidelity Small Cap Index Fund | 1.77M | 1.08% |
| Vanguard Strategic Equity Fund | 1.75M | 1.06% |
Insider trades
Form 4 filings by officers, directors and large holders
Over the last 6 months, insiders sold $658.52K (2 trades) of IRWD on the open market, with no buys.
| Insider | Type | Shares | Value |
|---|---|---|---|
| DENNER ALEXANDER J | Award | 3.69K | — |
| Silber Jeffrey | Award | 137.04K | — |
| Silver Ronald | Sale | 127.89K | $578.06K |
| Shepard Jay | Award | 63.48K | — |
| Kessler Marla L | Award | 63.48K | — |
| Currie Mark G | Award | 63.48K | — |
| Duane Jon R | Award | 63.48K | — |
| McHugh Julie | Sale | 21.57K | $80.46K |
| McHugh Julie | Award | 63.48K | — |
| Moukheibir Catherine | Award | 63.48K | — |
Short interest
Settled Sep 30, 2026
- Shares short
- 15.57M
- Days to cover
- 6.19
- % of shares outstanding
- 9.46%
- Average daily volume
- 2.52M
- Change since last report
- −16.9%
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