13F portfolio / Event-driven, activist
JANA Partners
Barry Rosenstein (founder)
JANA Partners is an activist and event-driven hedge fund founded by Barry Rosenstein in 2001.
- Reported 13F value
- $1.9B
- Positions
- 10
- Est. 1-yearEstimate
- -12.2%SPY +15.7%
- Est. 3-year, annualizedEstimate
- —SPY +22.8%
As of Jun 30, 2026 · filed Aug 14, 2026
Holdings
0 new · 3 added · 3 trimmed · 4 unchanged · 1 sold out
| 1 | MRCY on Yahoo Finance (opens in a new tab) | Mercury Sys IncCOM | 25.5% | $484M | 3,958,849 | Trimmed -3.6% | $35.43* | $72.31 | +104.1% |
| 2 | COO on Yahoo Finance (opens in a new tab) | Cooper Cos IncCOM | 13.5% | $257M | 3,582,480 | Unchanged | $72.13 | $57.76 | -19.9% |
| 3 | SPY on Yahoo Finance (opens in a new tab) | State Str SPDR S&P 500 ETF TTR UNIT | 13.5% | $256M | 342,965 | Unchanged | $474.71* | $762.97 | +60.7% |
| 4 | LW on Yahoo Finance (opens in a new tab) | Lamb Weston Hldgs IncCOM | 12.2% | $233M | 5,394,635 | Added +7.7% | $63.68 | $53.44 | -16.1% |
| 5 | FISV on Yahoo Finance (opens in a new tab) | Fiserv IncCOM | 9.4% | $180M | 3,662,080 | Trimmed -17.4% | $73.09 | $47.40 | -35.1% |
| 6 | MKL on Yahoo Finance (opens in a new tab) | Markel Group IncCOM | 7.9% | $150M | 76,743 | Added +1.9% | $1716.67 | $1841.96 | +7.3% |
| 7 | ALKT on Yahoo Finance (opens in a new tab) | Alkami Technology IncCOM | 6.4% | $122M | 6,747,707 | Added +24.2% | $21.67 | $13.61 | -37.2% |
| 8 | FUN on Yahoo Finance (opens in a new tab) | Six Flags Entertainment CorpCOM | 4.6% | $88M | 4,116,099 | Unchanged | $26.42 | $8.20 | -69.0% |
| 9 | P on Yahoo Finance (opens in a new tab) | Everpure IncCL A | 4.1% | $78M | 989,196 | Trimmed -5.1% | $67.73 | $125.00 | +84.5% |
| 10 | RPD on Yahoo Finance (opens in a new tab) | Rapid7 IncCOM | 2.9% | $55M | 6,749,936 | Unchanged | $33.01 | $12.42 | -62.4% |
Sold out since Q1 2026
- —Enhabit Inc$29M at Q1 2026
Estimated, from reported holdings
Quarter by quarter
High-conviction buys (new positions at 3% or more of the portfolio) since Q3 2023: 12. Of 10 with six months of history, 10.0% beat the S&P 500 from the filing date.
Source: SEC Form 13F-HR 0000902664-26-003486, compared with the Q1 2026 report. 0 option rows are excluded from weights. Tickers map from CUSIP via OpenFIGI. Estimated returns weight each position’s next-quarter total return (Yahoo Finance adjusted closes) by its quarter-end value and assume no trades. Estimated cost averages daily adjusted closes in each quarter the share count rose, from Q3 2023 onward (* = held at the start of our data). Price is the latest close.
Important information
Form 13F data is delayed. Managers have up to 45 days after each calendar quarter to file, so holdings shown may have changed materially since the report date. 13F reports cover long positions in US-listed equities and certain other securities only; they exclude short positions, most non-US holdings, cash, bonds and private investments, and managers may request confidential treatment for some positions. Options rows are listed in filings but are not counted in the holdings and weights shown here.
Estimated holdings returns, estimated cost and high-conviction results are hypothetical calculations from quarter-end holdings and public prices, assuming no trades between reports. They are not the actual returns or costs of any fund or manager and do not reflect fees, trading, leverage, shorts or cash. Biographies are drawn from cited public sources. This page is for information only and is not individualized investment advice or a recommendation to buy or sell any security. Gulfstream Capital and its clients may hold positions in securities shown.