JANA Partners Management, LP
Long book
$1.67B
Q1 2026
Positions
11
Top-10 weight
98%
concentration
Last quarter
+20.9%
SPY +14.8%
Turnover
23%
of book per quarter
Strategy in plain words
auto-generated from filingsJANA Partners Management, LP is an activist investor that takes positions to influence management, running a $1.67B US long book across 11 positions.
The portfolio is extremely concentrated — the top 10 positions are almost the whole book. Turnover is modest: positions are typically held for years. Current anchor positions: MERCURY SYSTEMS INC, COOPER COS INC/THE, FISERV INC, SS SPDR S&P 500 ETF TRUST-US, LAMB WESTON HOLDINGS INC.
Over the last 9 quarters its long book ran on average 0.9pp per quarter behind the S&P 500, beating the index in 4 of 9 quarters. We rate its filings highest-signal: new buys here are worth attention.
Implied long-book return vs S&P 500
methodology: positions priced quarterly, no shorts/options Fund long book S&P 500
Q1 2024
-2.5%
Q2 2024
+13.0%
Q3 2024
+6.5%
Q4 2024
-9.2%
Q1 2025
+7.7%
Q2 2025
+11.0%
Q3 2025
-4.5%
Q4 2025
-10.4%
Q1 2026
+20.9%
Sector allocation
Technology 33%
Services media 22%
Healthcare 18%
Consumer staples 15%
Financials 10%
Other 2%
Long book by quarter
What does JANA Partners own?
Q1 2026 13F| Company | Sector | Shares | Value | % of book | Change |
|---|---|---|---|---|---|
| MRCY MERCURY SYSTEMS INC | Technology | 4.1M | $299.5M | 18.0% | -17.2% |
| COO COOPER COS INC/THE | Healthcare | 3.6M | $254.9M | 15.3% | +1.3% |
| FISV FISERV INC | Services media | 4.4M | $247.5M | 14.8% | +97.5% |
| LW LAMB WESTON HOLDINGS INC | Consumer staples | 5.0M | $211.7M | 12.7% | Held |
| MKL MARKEL GROUP INC | Financials | 75.3K | $144.1M | 8.6% | -7.3% |
| ALKT ALKAMI TECHNOLOGY INC | Technology | 5.4M | $85.1M | 5.1% | +11.0% |
| FUN SIX FLAGS ENTERTAINMENT CORP | Services media | 4.1M | $73.1M | 4.4% | Held |
| P EVERPURE INC-A | Technology | 1.0M | $61.5M | 3.7% | New |
| RPD RAPID7 INC | Technology | 6.7M | $37.2M | 2.2% | Held |
| EHABUSD ENHABIT INC | — | 2.1M | $29.5M | 1.8% | Held |
13F filing history
| Period | Form | Filed | Entries | Reported value | Flags | Source |
|---|---|---|---|---|---|---|
| Q1 2026 | 13F-HR/ANEW HOLDINGS | Jun 30, 2026 | 1 | $61.5M | canonical | SEC ↗ |
| Q1 2026 | 13F-HR | May 15, 2026 | 10 | $1.61B | confidential canonical | SEC ↗ |
| Q4 2025 | 13F-HR | Feb 17, 2026 | 12 | $1.92B | canonical | SEC ↗ |
| Q3 2025 | 13F-HR | Nov 14, 2025 | 12 | $2.07B | canonical | SEC ↗ |
| Q2 2025 | 13F-HR | Aug 14, 2025 | 10 | $1.99B | canonical | SEC ↗ |
| Q1 2025 | 13F-HR | May 15, 2025 | 10 | $1.94B | canonical | SEC ↗ |
| Q4 2024 | 13F-HR | Feb 14, 2025 | 11 | $2.03B | canonical | SEC ↗ |
| Q3 2024 | 13F-HR | Nov 14, 2024 | 12 | $1.93B | canonical | SEC ↗ |
| Q2 2024 | 13F-HR | Aug 14, 2024 | 12 | $1.71B | canonical | SEC ↗ |
| Q1 2024 | 13F-HR | May 15, 2024 | 10 | $1.83B | canonical | SEC ↗ |