Barry Rosenstein portfolio: what JANA Partners holds
The founder of the activist fund JANA Partners, which pushes for changes in company management and strategy.
Stock portfolio value
$1.9B
Stock positions
10
Report date
30 June 2026
Filed
14 August 2026
Largest positions
| # | Company | Weight | Value | Last quarter |
|---|---|---|---|---|
| 1 | Mercury Sys IncMRCY | 25.5% | $484.3M | Trimmed -4% |
| 2 | Cooper Cos IncCOO | 13.5% | $256.9M | — |
| 3 | State Str Spdr S&P 500 Etf TSPY | 13.5% | $256.1M | — |
| 4 | Lamb Weston Hldgs IncLW | 12.2% | $232.9M | Added +8% |
| 5 | Fiserv IncFISV | 9.4% | $179.6M | Trimmed -17% |
| 6 | Markel Group IncMKL | 7.9% | $149.9M | Added +2% |
| 7 | Alkami Technology IncALKT | 6.4% | $122.3M | Added +24% |
| 8 | Six Flags Entertainment CorpFUN | 4.6% | $87.7M | — |
| 9 | Everpure IncP | 4.1% | $77.9M | New |
| 10 | Rapid7 IncRPD | 2.9% | $54.7M | — |
New positions last quarter
- Everpure Inc$77.9M
Positions sold
- Enhabit Inc$29.5M
Source: SEC filing. Values count stock positions only; options are left out of the totals and tables.
How to use this page
A 13F filing shows what a manager held on the last day of a quarter, published up to 45 days later. It is a snapshot, not a trading signal: the manager may already have bought or sold since. Learn more in How to read 13F filings.
For information only, not investment advice. 13F filings are delayed by up to 45 days and do not show cash, bonds, short positions or non-US stocks.