Barry Rosenstein JANA Partners Management
Barry Rosenstein is the founder of JANA Partners, an activist and event-driven investment firm. JANA is known for campaigns seeking strategic change, improved capital returns, and better operational execution at public companies. Rosenstein’s efforts have spanned consumer, industrial, and technology-related businesses over many years.
Top Buys
| Rank | Stock | Value |
|---|---|---|
| 1 |
FISV
Fiserv Inc
FISV
|
+$136M |
| 2 |
P
Everpure Inc
P
|
+$70.6M |
| 3 |
Alkami Technology
ALKT
|
+$9.88M |
| 4 |
Cooper Companies
COO
|
+$3.6M |
Top Sells
| Rank | Stock | Value |
|---|---|---|
| 1 |
THS
Treehouse Foods
THS
|
+$137M |
| 2 |
Mercury Systems
MRCY
|
+$74.2M |
| 3 |
Freshpet
FRPT
|
+$34M |
| 4 |
State Street SPDR S&P 500 ETF Trust
SPY
|
+$32.4M |
| 5 |
Markel Group
MKL
|
+$12M |
Sector Composition
| Rank | Sector | Weight |
|---|---|---|
| 1 | Technology | 25.87% |
| 2 | Industrials | 17.96% |
| 3 | Healthcare | 17.05% |
| 4 | Consumer Staples | 12.69% |
| 5 | Financials | 8.64% |
| Name | Market Value | Portfolio Weight | Shares or Principal |
Change in Stake | Capital Flow | |
|---|---|---|---|---|---|---|
|
1
Mercury Systems
MRCY
$5.49B
| $299M | 17.96% |
4,107,424
-852,057
| -17% | -$74.2M |
|
|
2
Cooper Companies
COO
$14.9B
| $255M | 15.29% |
3,565,158
+45,538
| +1% | +$3.6M |
|
|
FISV
3
Fiserv Inc
FISV
$28B
| $248M | 14.84% |
4,435,605
+2,190,085
| +98% | +$136M |
|
|
4
State Street SPDR S&P 500 ETF Trust
SPY
$809B
| $223M | 13.4% |
343,665
-47,672
| -12% | -$32.4M |
|
5
Lamb Weston
LW
$7.38B
| $212M | 12.69% |
5,008,635
| – | – |
|
|
6
Markel Group
MKL
$22.2B
| $144M | 8.64% |
75,307
-5,912
| -7% | -$12M |
|
|
7
Alkami Technology
ALKT
$2.18B
| $85.1M | 5.1% |
5,431,388
+536,723
| +11% | +$9.88M |
|
8
Cedar Fair
FUN
$1.71B
| $73.1M | 4.38% |
4,116,099
| – | – |
|
|
P
9
Everpure Inc
P
$36.1B
| $61.5M | 3.69% |
+1,042,296
| New | +$70.6M |
|
10
Rapid7
RPD
$799M
| $37.2M | 2.23% |
6,743,653
| – | – |
|
|
EHAB
11
DELISTED
Enhabit
EHAB
| $29.5M | 1.77% |
2,090,412
| – | – |
|
|
12
Freshpet
FRPT
$3.55B
| – | – |
-557,390
| Closed | -$34M |
|
|
THS
13
DELISTED
Treehouse Foods
THS
| – | – |
-5,821,337
| Closed | -$137M |
|
Similar funds
Barry Rosenstein's Q1 2026 Portfolio in Review
As of Q1 2026, Barry Rosenstein held 13 positions worth $1.67B, down 13% from $1.92B the previous quarter. Its ten largest holdings account for 98% of the portfolio.
Barry Rosenstein withdrew a net $70.3M in Q1 2026, closing 2 positions and reducing 3 holdings. Its most notable exit was Treehouse Foods, an estimated $137M position sold in full.
By sector, the portfolio is most concentrated in Technology at 26% of assets, up from 19% a quarter earlier, followed by Industrials and Healthcare.
Against the trend, Barry Rosenstein opened a new position in Everpure Inc worth $61.5M.
- Barry Rosenstein's largest Q1 2026 buy was Everpure Inc: 1,042,296 shares worth $61.5M.
- Barry Rosenstein added most to Fiserv Inc in Q1 2026, an estimated $136M increase.
- Barry Rosenstein's biggest Q1 2026 reduction was Mercury Systems, cutting an estimated $74.2M.
- Barry Rosenstein fully exited Treehouse Foods in Q1 2026, selling an estimated $137M.
- Barry Rosenstein's ten largest holdings make up 98% of its $1.67B portfolio in Q1 2026.
- Barry Rosenstein opened 1 new position and closed 2 in Q1 2026.
- Barry Rosenstein's portfolio value fell 13% quarter-over-quarter to $1.67B.
Based on JANA Partners Management's 13F filing for Q1 2026, filed 15 May 2026.