Ironwood Pharmaceuticals, Inc.
Ironwood Pharmaceuticals, Inc. (IRWD) Stock Ownership
Institutional vs insider vs public ownership from 13F and float data — top holders, activity, and insider trades below.
SEC 13F · FMP · IRWD · as of Sep 30, 2025
Ownership Breakdown
169
Institutional Holders
▲ 12 vs Q2
$195.27M
Total Inst. Value
▲ $90.16M vs Q2
164.61M
Shares Outstanding
freeFloat 96.14%
148.97M
13F Shares Held
▲ 2.46M vs Q2
Institutional ownership = 13F shares ÷ total outstanding. Insider % = 100 − free float. Public % = free float − institution %. Data: FMP /symbol-positions-summary + /shares-float + SEC EDGAR.
Top Institutional Holders
IRWD largest shareholders · institutional ownership
Q3 2025 · SEC 13F
Showing top 10 holders
| Holder | Shares | % Owned | Weight | Value | Reported | Change |
|---|---|---|---|---|---|---|
ARMISTICE CAPITAL, LLC pharmaceutical preparations | 16.15M | 9.99% | 9.99% | $21.16B | Nov 17, 2025 | — held |
VANGUARD GROUP INC pharmaceutical preparations | 16.07M | 9.94% | 9.94% | $21.05B | Nov 7, 2025 | ▼ 130.1K |
SARISSA CAPITAL MANAGEMENT LP pharmaceutical preparations | 15.92M | 9.84% | 9.84% | $20.85B | Nov 14, 2025 | — held |
BLACKROCK, INC. pharmaceutical preparations | 12.06M | 7.46% | 7.46% | $15.80B | Nov 12, 2025 | ▲ 39.6K |
BANK OF AMERICA CORP /DE/ pharmaceutical preparations | 11.70M | 7.23% | 7.23% | $15.32B | Feb 3, 2026 | ▲ 8.34M |
UBS GROUP AG pharmaceutical preparations | 11.20M | 6.93% | 6.93% | $14.67B | Nov 13, 2025 | — held |
RENAISSANCE TECHNOLOGIES LLC pharmaceutical preparations | 8.35M | 5.16% | 5.16% | $10.94B | Nov 13, 2025 | ▼ 54.0K |
ACADIAN ASSET MANAGEMENT LLC pharmaceutical preparations | 6.50M | 4.02% | 4.02% | $8.51B | Nov 13, 2025 | ▼ 47.2K |
KYNAM CAPITAL MANAGEMENT, LP pharmaceutical preparations | 5.47M | 3.38% | 3.38% | $7.16B | Nov 14, 2025 | — held |
AQR CAPITAL MANAGEMENT LLC pharmaceutical preparations | 5.38M | 3.33% | 3.33% | $7.05B | Nov 14, 2025 | ▼ 787.1K |
Data from SEC Form 13F filings. Ownership bar normalised to largest holder. Change flags: isNew / isSoldOut / changeInSharesNumber (FMP extract-analytics/holder).
Institutional Activity
Q3 2025 vs prior quarter
Q3 2025
21
Increased
+12.52M shares1
New Positions
first time holders21
Decreased
−5.39M shares0
Sold Out
fully exitedNet shares change (top 50)
+7.13M
+12.52M / −5.39M
Net new holders
+1
1 new / 0 exited
Based on top 50 institutional holders by position size. Fields: isNew, isSoldOut, changeInSharesNumber (FMP extract-analytics/holder, limit=50).
Insider Buying vs Selling
IRWD insider trading · insider activity
Source: SEC Form 4
Insiders have been primarily selling shares recently. Selling may be driven by pre-scheduled Rule 10b5-1 plans rather than negative sentiment.
1
Buy transactions
0
Sell transactions
0.00
Buy/Sell ratio
$0M
Total disposed
Recent Insider Transactions
Showing 10 most recent · Common Stock only
| Name · Role | Date | Type | Shares | Price | Value | After Trans. | Filing |
|---|---|---|---|---|---|---|---|
Silver Ronald PFO & PAO | May 19, 2026 | Award | 25,000 | — | — | 441.6K | Form 4 ↗ |
DENNER ALEXANDER J director | Mar 17, 2026 | Sale | 6,725,000 | $3.05 | $20.51M | 9.19M | Form 4 ↗ |
DENNER ALEXANDER J director | Mar 17, 2026 | Sale | 5,800 | $3.31 | $19.2K | 9.19M | Form 4 ↗ |
DENNER ALEXANDER J director | Mar 13, 2026 | Award | 4,451 | — | — | 256.3K | Form 4 ↗ |
John Minardo Chief Legal Officer | Mar 10, 2026 | Award | 136,612 | — | — | 500.5K | Form 4 ↗ |
Martini Gregory S. Chief Financial Officer | Mar 10, 2026 | Award | 136,612 | — | — | 297.2K | Form 4 ↗ |
Gaskins Tammi L Chief Commercial Officer | Mar 10, 2026 | Award | 136,612 | — | — | 350.4K | Form 4 ↗ |
Shetzline Michael SVP, CMO, Head-Res&Drug | Mar 10, 2026 | Award | 136,612 | — | — | 658.0K | Form 4 ↗ |
Silver Ronald Principal Accounting Officer | Mar 10, 2026 | Award | 163,934 | — | — | 416.6K | Form 4 ↗ |
MCCOURT Thomas A Chief Executive Officer | Mar 10, 2026 | Award | 409,836 | — | — | 1.90M | Form 4 ↗ |
Source: /insider-trading/search (FMP stable). Buy/Sell direction: acquisitionOrDisposition A=Buy, D=Sell. RSU vesting (M-Exempt) excluded from sentiment bar. All data from SEC EDGAR public filings.
About institutional & insider ownership
Ironwood Pharmaceuticals, Inc. (IRWD) is primarily owned by institutional investors, who hold approximately 90.5% of total shares outstanding. Company insiders own approximately 3.86%, while retail and public investors account for the remaining 5.65%.
The largest institutional shareholder of Ironwood Pharmaceuticals, Inc. is ARMISTICE CAPITAL, LLC, holding approximately 16.15 million shares — equal to 9.99% of outstanding shares — as of September 30, 2025.
A total of 169 institutional investors currently hold IRWD stock, with a combined institutional value of approximately $195,267,565 as of the most recent 13F filing period.
Frequently asked questions
IRWD ownershipIronwood Pharmaceuticals, Inc. (IRWD) is primarily owned by institutional investors, who hold approximately 90.5% of shares. The largest shareholder is ARMISTICE CAPITAL, LLC with a 9.99% stake. Company insiders hold 3.86%. Data sourced from SEC Form 13F as of September 30, 2025.