JANA Partners Management, LP · Q2 2026 13F · SEC CIK 1998597
Barry Rosenstein portfolio
Hedge fundJANA Partners 13F holdings. Filed 2026-08-14 for Q2 2026. Open the filing ↗ · All SEC filings ↗
- Reported 13F value
- $1.9B
- Reported positions
- 10
- Top holdings a year, 3 yrs
- +17.0%
- Assets under management
- $2.3B
Barry Rosenstein is the founder of JANA Partners, which reported 10 positions worth $1.9B in its Q2 2026 13F, filed 2026-08-14. Its largest holdings were Mercury Sys Inc (MRCY, 25.5%), Cooper Cos Inc (COO, 13.5%), State Str Spdr S&p 500 ETF T (SPY, 13.5%). A portfolio copying its top holdings returned 17.0% a year over the last 3 years, against 21.8% for the S&P 500.
Barry Rosenstein holdings all 10 positions.
Weights are shares of the filer's total reported 13F value, compared with Q1 2026. Share changes may reflect splits; weight changes also reflect price moves. A 13F shows long US-listed positions only, up to 135 days after the fact.
| Stock | % of 13F value | Share change | Reported value |
|---|---|---|---|
| MRCYMercury Sys Inc | 25.5% | -3.6% | $484.3M |
| COOCooper Cos Inc | 13.5% | +0.5% | $256.9M |
| SPYState Str Spdr S&p 500 ETF T | 13.5% | -0.2% | $256.1M |
| LWLamb Weston Hldgs Inc | 12.2% | +7.7% | $232.9M |
| FISVFiserv Inc | 9.4% | -17.4% | $179.6M |
| MKLMarkel Group Inc | 7.9% | +1.9% | $149.9M |
| ALKTAlkami Technology Inc | 6.4% | +24.2% | $122.3M |
| FUNSix Flags Entertainment Corp | 4.6% | +0.0% | $87.7M |
| PSTGEverpure Inc | 4.1% | — | $77.9M |
| RPDRapid7 Inc | 2.9% | +0.1% | $54.7M |
What Barry Rosenstein bought and sold in Q2 2026, against Q1 2026.
New positions
- PSTG Everpure Inc4.1% of 13F
Added to
- ALKT Alkami Technology Inc+24.2% shares
- LW Lamb Weston Hldgs Inc+7.7% shares
Reduced
- FISV Fiserv Inc-17.4% shares
Sold out
- EHAB Enhabit, Inc.was 1.8%
Share counts compared with the Q1 2026 13F; a split also changes share counts.
How the holdings did against the S&P 500.
- 1 year
- +12.1% /yr
- S&P 500 +20.1%
- 3 years
- +17.0% /yr
- S&P 500 +21.8%
- 5 years
- —
A portfolio of the filer's 20 largest 13F positions, weighted by value, bought the trading day after each 13F was filed and held until the next one was: what copying this filer could have earned. 13Fs show long US-listed positions only, so this is an estimate of the stock picks, not the fund's reported returns.
Reported 13F value by quarter.
| Quarter | 13F value | Positions |
|---|---|---|
| Q2 2026 | $1.9B | 10 |
| Q1 2026 | $1.6B | 10 |
| Q4 2025 | $1.9B | 12 |
| Q3 2025 | $2.1B | 12 |
| Q2 2025 | $2.0B | 10 |
| Q1 2025 | $1.9B | 10 |
| Q4 2024 | $1.9B | 10 |
| Q3 2024 | $1.8B | 11 |
| Q2 2024 | $1.7B | 12 |
| Q1 2024 | $1.8B | 10 |
| Q4 2023 | $1.5B | 8 |
| Q3 2023 | $1.4B | 8 |
Questions about Barry Rosenstein's portfolio
Who is Barry Rosenstein?
Barry Rosenstein is the founder of JANA Partners, a hedge fund that files its US stock holdings with the SEC on Form 13F under the name JANA Partners Management, LP.
What stocks does Barry Rosenstein own?
JANA Partners Management, LP's latest 13F, for Q2 2026 and filed Aug 14, 2026, lists 10 positions worth $1.9B. The largest are Mercury Sys Inc (MRCY) at 25.5%, Cooper Cos Inc (COO) at 13.5%, State Str Spdr S&p 500 ETF T (SPY) at 13.5%, Lamb Weston Hldgs Inc (LW) at 12.2% and Fiserv Inc (FISV) at 9.4%.
What did Barry Rosenstein buy last quarter?
In Q2 2026, JANA Partners Management, LP added a new position in Everpure Inc (PSTG), Alkami Technology Inc (ALKT) (+24.2% shares) and Lamb Weston Hldgs Inc (LW) (+7.7% shares), compared with its Q1 2026 filing.
What did Barry Rosenstein sell last quarter?
In Q2 2026, JANA Partners Management, LP sold all of Enhabit, Inc. (EHAB) and Fiserv Inc (FISV) (-17.4% shares), compared with its Q1 2026 filing.
How has Barry Rosenstein's portfolio performed?
A portfolio copying JANA Partners Management, LP's 20 largest 13F holdings each quarter, from the day each filing was public, returned +17.0% a year over the last 3 years, against +21.8% for the S&P 500. Over 1 year: +12.1% against +20.1%.
When is JANA Partners Management, LP's next 13F filing due?
13F filings are due 45 days after each quarter ends. JANA Partners Management, LP's filing for the quarter ending Sep 30, 2026 is due by Nov 14, 2026; this page updates the day after it is published.
How much money does JANA Partners Management, LP manage?
JANA Partners Management, LP reported $2.3B of regulatory assets under management on its latest SEC Form ADV. Its 13F, which covers only US-listed stocks and options, totals $1.9B.