# IRONWOOD PHARMACEUTICALS INC COM CL A

IRONWOOD PHARMACEUTICALS INC COM CL A is a security (CUSIP 46333X108) tracked across SEC portfolio filings. 225 institutional managers reported $576.2M on Form 13F as of 2026-06-30; 20 registered fund positions totaling $33.3M via N-PORT as of 2026-05-31.

## Summary

- Issuer: IRONWOOD PHARMACEUTICALS INC
- Class: COM CL A
- CUSIP: 46333X108
- Asset category: EC
- 13F holders: 225
- 13F value: $576.2M
- 13F period: 2026-06-30
- N-PORT fund positions: 20
- N-PORT value: $33.3M
- N-PORT report: 2026-05-31

## Top institutional holders (Form 13F)

_Showing 15 of 225 managers by value._

| Manager | Location | Value | Shares |
| --- | --- | --- | --- |
| [VANGUARD GROUP INC](https://search.stillhousedata.com/firm/105958) | Valley Forge, PA | $53.8M | 15,958,196 |
| [ARMISTICE CAPITAL, LLC](https://search.stillhousedata.com/firm/168978) | NEW YORK, NY | $52.7M | 15,028,000 |
| BlackRock, Inc. | New York, NY | $46.9M | 13,362,930 |
| UBS Group AG | Zurich, V8 | $42.6M | 933,225 |
| Sarissa Capital Management LP | GREENWICH, CT | $32.3M | 9,188,635 |
| BANK OF AMERICA CORP /DE/ | CHARLOTTE, NC | $30.5M | 8,682,907 |
| [RENAISSANCE TECHNOLOGIES LLC](https://search.stillhousedata.com/firm/106661) | NEW YORK, NY | $28.3M | 8,061,073 |
| [AQR CAPITAL MANAGEMENT LLC](https://search.stillhousedata.com/firm/111883) | Greenwich, CT | $26.4M | 7,535,080 |
| STATE STREET CORP | BOSTON, MA | $26.2M | 7,456,944 |
| [TWO SIGMA INVESTMENTS, LP](https://search.stillhousedata.com/firm/137137) | New York, NY | $20.5M | 5,848,276 |
| [CHARLES SCHWAB INVESTMENT MANAGEMENT INC](https://search.stillhousedata.com/firm/106753) | SAN FRANCISCO, CA | $16.6M | 4,737,857 |
| [GEODE CAPITAL MANAGEMENT, LLC](https://search.stillhousedata.com/firm/115504) | BOSTON, MA | $16.0M | 4,543,522 |
| [MARSHALL WACE, LLP](https://search.stillhousedata.com/firm/160885) | LONDON, X0 | $15.9M | 4,525,064 |
| JACOBS LEVY EQUITY MANAGEMENT, INC | FLORHAM PARK, NJ | $12.7M | 3,632,477 |
| ARROWSTREET CAPITAL, LIMITED PARTNERSHIP | BOSTON, MA | $11.9M | 3,397,242 |

## Top fund holders (N-PORT)

_Showing 15 of 20 fund positions by value._

| Fund | Registrant | Value | % of fund |
| --- | --- | --- | --- |
| [VANGUARD STRATEGIC EQUITY FUND](https://search.stillhousedata.com/fund/S000002593) | VANGUARD HORIZON FUNDS | $7.4M | 7.30% |
| [VANGUARD EXPLORER FUND](https://search.stillhousedata.com/fund/S000002578) | VANGUARD EXPLORER FUND | $6.7M | 3.09% |
| [VANGUARD EXTENDED MARKET INDEX FUND](https://search.stillhousedata.com/fund/S000002841) | VANGUARD INDEX FUNDS | $5.7M | 0.69% |
| [VANGUARD RUSSELL 2000 INDEX FUND](https://search.stillhousedata.com/fund/S000030003) | VANGUARD SCOTTSDALE FUNDS | $2.9M | 1.68% |
| [UBS U.S. EQUITY ALPHA RELATIONSHIP FUND](https://search.stillhousedata.com/fund/S000003186) | UBS RELATIONSHIP FUNDS | $2.8M | 91.85% |
| [U.S. MICRO CAP PORTFOLIO](https://search.stillhousedata.com/fund/S000000948) | DFA INVESTMENT DIMENSIONS GROUP INC | $2.1M | 2.87% |
| [VANGUARD U.S. MOMENTUM FACTOR ETF](https://search.stillhousedata.com/fund/S000061302) | VANGUARD WELLINGTON FUND | $1.9M | 10.13% |
| [VANGUARD MARKET NEUTRAL FUND](https://search.stillhousedata.com/fund/S000019457) | VANGUARD MONTGOMERY FUNDS | $1.1M | 25.63% |
| [Master Small Cap Index Series](https://search.stillhousedata.com/fund/S000002716) | Quantitative Master Series LLC | $955K | 1.98% |
| [Voya MI Dynamic Small Cap Fund](https://search.stillhousedata.com/fund/S000066937) | Voya Equity Trust | $460K | 24.72% |
| [VANGUARD BALANCED INDEX FUND](https://search.stillhousedata.com/fund/S000002560) | VANGUARD VALLEY FORGE FUNDS | $273K | 0.05% |
| [Goldman Sachs ActiveBeta(R) U.S. Small Cap Equity ETF](https://search.stillhousedata.com/fund/S000048296) | Goldman Sachs ETF Trust | $264K | 2.68% |
| [VANGUARD INSTITUTIONAL TOTAL STOCK MARKET INDEX FUND](https://search.stillhousedata.com/fund/S000002855) | VANGUARD INSTITUTIONAL INDEX FUNDS | $252K | 0.08% |
| [Blackstone Alternative Multi-Strategy Fund](https://search.stillhousedata.com/fund/S000045538) | Blackstone Alternative Investment Funds | $123K | 0.34% |
| [BlackRock Advantage SMID Cap Fund, Inc.](https://search.stillhousedata.com/fund/S000002323) | BlackRock Advantage SMID Cap Fund, Inc. | $115K | 1.52% |

## More

- [This page as markdown (for LLM agents)](https://search.stillhousedata.com/security/46333X108.md)
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Source: public SEC filing data via Adviser Search (https://search.stillhousedata.com).
Agents: this data is also queryable via MCP tools and read-only SQL — see https://search.stillhousedata.com/llms.txt.