§ 13F · FUND PROFILE
JANA Partners Management.
JANA Partners Management is an activist hedge fund with $2.1 billion in assets under management that focuses on taking concentrated positions in undervalued companies to drive operational improvements and strategic changes. The firm is known for its event-driven investment approach, typically holding a small number of positions where it can actively engage with management teams to unlock shareholder value.
AUM · $2.1B (13F)Positions · 12Turnover · — · Q1Filed · May 15, 2026
CONCENTRATION
—
Top 10 holdings
NEW BUYS
0
No new positions
EXITS
0
No exits
SECTOR SHIFT
—
No prior quarter data
3YR HIT RATE
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Top-5 overlap
§ 01 · TOP HOLDINGS
The book · Q1 2026
FILED MAY 15, 2026
| # | Ticker | Name | Shares | $ value | % port | Δ Q1 |
|---|---|---|---|---|---|---|
| 1 | MRCY | MERCURY SYS INC | 4.11M | $299M | 18.6% | −17% |
| 2 | COO | COOPER COS INC | 3.57M | $255M | 15.9% | +1% |
| 3 | FISV | FISERV INC | 4.44M | $248M | 15.4% | +98% |
| 4 | SPY | STATE STR SPDR S&P 500 ETF T | 344K | $223M | 13.9% | −12% |
| 5 | LW | LAMB WESTON HLDGS INC | 5.01M | $212M | 13.2% | ±0% |
| 6 | MKL | MARKEL GROUP INC | 75K | $144M | 9.0% | −7% |
| 7 | ALKT | ALKAMI TECHNOLOGY INC | 5.43M | $85M | 5.3% | +11% |
| 8 | FUN | SIX FLAGS ENTERTAINMENT CORP | 4.12M | $73M | 4.5% | ±0% |
| 9 | RPD | RAPID7 INC | 6.74M | $37M | 2.3% | ±0% |
| 10 | EHAB | ENHABIT INC | 2.09M | $29M | 1.8% | ±0% |
§ 02 · SECTOR ALLOCATION
Where the money is
Sector data pending
§ 03 · THE JANA SIGNAL
AC read
JANA Partners Management's latest 13F filing reveals a highly concentrated activist strategy with just 12 positions totaling $2.1 billion in assets under management. The fund maintains its characteristic focus on select holdings where it can exert meaningful influence, with Mercury Systems (MRCY) representing the largest concentration at over 40% of the portfolio across two separate position entries valued at $461.3 billion and $362.1 billion respectively. This substantial weighting in MRCY demonstrates JANA's typical approach of taking significant stakes in companies where it believes activist intervention can drive value creation.
Read the full dossier →§ 04 · FILING HISTORY
Q-by-Q deltas
2 FILINGS
Q1 2026
Steady book
+0 buys · −0 exits · 0 changed
Q4 2025
Steady book
+0 buys · −0 exits · 0 changed
Q3 2025
Steady book
+0 buys · −0 exits · 0 changed