Barry Rosenstein's portfolio
Activist value with ESG and operational improvement focus.
What changed in Q2 2026
Compared with the previous 13F. Values are as reported at quarter end. How to read a 13F.
New positions
None this quarter.
Added to
- Cooper CompaniesCOO$257M
- Lamb WestonLW$233M
- MarkelMKL$150M
- Alkami TechnologyALKT$122M
- RPDRPD$55M
Trimmed
- MRCYMRCY$484M
- SPYSPY$256M
- Fiserv, Inc. Common StockFISV$180M
- EverpureP$78M
Sold out
None this quarter.
Holdings
10 US-listed positions in the Q2 2026 13F, largest first.
| Stock | % of portfolio | Value | Shares | Last quarter |
|---|---|---|---|---|
| MRCYMRCY | 25.46% | $484M | 3,958,849 | Trimmed |
| Cooper CompaniesCOO | 13.51% | $257M | 3,582,480 | Added |
| SPYSPY | 13.46% | $256M | 342,965 | Trimmed |
| Lamb WestonLW | 12.24% | $233M | 5,394,635 | Added |
| Fiserv, Inc. Common StockFISV | 9.44% | $180M | 3,662,080 | Trimmed |
| MarkelMKL | 7.88% | $150M | 76,743 | Added |
| Alkami TechnologyALKT | 6.43% | $122M | 6,747,707 | Added |
| Six Flags EntertainmentFUN | 4.61% | $88M | 4,116,099 | Held |
| EverpureP | 4.10% | $78M | 989,196 | Trimmed |
| RPDRPD | 2.87% | $55M | 6,749,936 | Added |
By sector
Share of the reported value.
Reported value over time
Total 13F value at each quarter end.
Questions
What stocks does Barry Rosenstein own?
In the Q2 2026 13F, JANA Partners reported 10 US stock positions worth $1.9B. The largest: MRCY (MRCY) 25.5%, Cooper Companies (COO) 13.5%, SPY (SPY) 13.5%, Lamb Weston (LW) 12.2%, Fiserv, Inc. Common Stock (FISV) 9.4%.
What did Barry Rosenstein buy last quarter?
In Q2 2026: added to Cooper Companies (COO); added to Lamb Weston (LW); added to Markel (MKL).
When is Barry Rosenstein's next 13F?
13F filings are due 45 days after each quarter ends. The Q3 2026 filing is due by November 14, 2026.
More investors
13F filings list US-listed long positions (and some options) held at quarter end. They leave out short positions, cash, bonds and non-US holdings, and arrive up to 45 days after the quarter ends, so the investor may have traded since. Information only, not investment advice.