JANA Partners Management, LP — 13F Holdings & Portfolio
CIK 1998597 · latest 13F-HR filed 2026-05-15
JANA Partners Management, LP manages $1.61B in 13F-reported U.S. long-equity assets across 10 reported positions as of its 2026-03-31 13F-HR filing. Its largest disclosed positions are MRCY (18.65%), COO (15.87%), FISV (15.41%). Quarter over quarter (versus its 2025-12-31 filing) the fund opened 0 new positions, exited 2, added to 3, and trimmed 6.
AUM is the long-equity portion reported on Form 13F-HR. Excludes short positions, cash, foreign holdings, and non-13F assets. For informational purposes only — not investment advice.
$1.61B
Long-equity book
10
Distinct positions
2026-03-31
Filed 2026-05-15
+0 / −2 / ↑3 / ↓6
vs 2025-12-31
| Name | Title / Status | Ownership | Type |
|---|
Top Adds (vs prior quarter)
- FISERV INC$96.7M +64.1%
- ENHABIT INC$10.2M +52.8%
- SIX FLAGS ENTERTAINMENT CORP$9.9M +15.7%
Top Trims
- RAPID7 INC-$65.3M -63.8%
- MERCURY SYS INC-$62.6M -17.3%
- STATE STR SPDR S&P 500 ETF T-$43.4M -16.2%
- COOPER COS INC-$33.6M -11.6%
- MARKEL GROUP INC-$30.4M -17.4%
Rows tagged Call or Put are options positions, not stock. Per SEC Form 13F-HR, Value shows the notional value of the underlying (shares covered × underlying price), not the option premium. Shares is the number of underlying shares covered (divide by 100 for contract count).
| # | Issuer | Symbol | CUSIP | Value | Weight | Shares | Type |
|---|---|---|---|---|---|---|---|
| 1 | MERCURY SYS INC | MRCY | 589378108 | $299.5M | 18.65% | 4,107,424 | SH |
| 2 | COOPER COS INC | COO | 216648501 | $254.9M | 15.87% | 3,565,158 | SH |
| 3 | FISERV INC | FISV | 337738108 | $247.5M | 15.41% | 4,435,605 | SH |
| 4 | STATE STR SPDR S&P 500 ETF T | SPY | 78462F103 | $223.5M | 13.92% | 343,665 | SH |
| 5 | LAMB WESTON HLDGS INC | LW | 513272104 | $211.7M | 13.18% | 5,008,635 | SH |
| 6 | MARKEL GROUP INC | MKL | 570535104 | $144.1M | 8.98% | 75,307 | SH |
| 7 | ALKAMI TECHNOLOGY INC | ALKT | 01644J108 | $85.1M | 5.30% | 5,431,388 | SH |
| 8 | SIX FLAGS ENTERTAINMENT CORP | FUN | 83001C108 | $73.1M | 4.55% | 4,116,099 | SH |
| 9 | RAPID7 INC | RPD | 753422104 | $37.2M | 2.31% | 6,743,653 | SH |
| 10 | ENHABIT INC | EHAB | 29332G102 | $29.5M | 1.83% | 2,090,412 | SH |
| Period | Filed | AUM | Holdings | Accession |
|---|---|---|---|---|
| 2026-03-31 | 2026-05-15 | $1.61B | 10 | 0000902664-26-002515 |
| 2025-12-31 | 2026-02-17 | $1.92B | 12 | 0000902664-26-001069 |
| 2025-09-30 | 2025-11-14 | $2.07B | 12 | 0000902664-25-005066 |