JANA Partners Management, LP

In its 13F for Q3 2025 (holdings as of September 30, 2025, filed November 14, 2025), JANA Partners Management, LP reported 12 stock positions worth $2.1 billion. Its top holding was Mercury Systems (MRCY) at 22.3% of the portfolio, followed by Lamb Weston (LW, 14.1%) and Markel (MKL, 13.6%). Compared with Q2 2025, it opened 3 new positions, sold out of 1, added to 2 and reduced 5. The biggest buy was a new position in Cooper Cos (COO) and the biggest sale Trimble (TRMB, shares −48%).

Most Recent 13F
Q2 2026
Location
NEW YORK, NY
CIK
0001998597
Portfolio Value
$2.1B (Q3 2025)
SEC Filing
0000902664-25-005066 ↗ filed Nov 14, 2025

Holdings Value

0$500.0M$1.0B$1.5B$2.0B$2.5B Q1 2024: $1.8B Q1 2024 Q2 2024: $1.7B Q2 2024 Q3 2024: $1.8B Q3 2024 Q4 2024: $1.9B Q4 2024 Q1 2025: $1.9B Q1 2025 Q2 2025: $2.0B Q2 2025 Q3 2025: $2.1B $2.1B Q3 2025 Q4 2025: $1.9B Q4 2025 Q1 2026: $1.7B Q1 2026 Q2 2026: $1.9B Q2 2026

Holdings 12 stocks · $2.1B
MRCY Mercury Systems Inc. 22.33% 5,959,481 $461.3M Reduce -11.8%
LW Lamb Weston Holdings Inc. 14.08% 5,008,635 $290.9M Reduce -30.8%
MKL Markel Group Inc. 13.64% 147,411 $281.8M Reduce -2.7%
SPY SS SPDR S&P 500 ETF Trust-US 12.47% 386,637 $257.6M Reduce -24.6%
COO The Cooper Cos Inc. 8.08% 2,434,607 $166.9M New
TRMB Trimble Inc. 7.44% 1,881,399 $153.6M Reduce -47.9%
RPD RAPID7 Inc. 5.90% 6,502,108 $121.9M Add +13.5%
THS Treehouse Foods Inc. 5.70% 5,821,337 $117.6M No change
FUN Six Flags Entertainment Corp. 4.45% 4,049,940 $92.0M New
FRPT Freshpet Inc. 2.80% 1,048,136 $57.8M Add +4.1%
ALKT Alkami Technology Inc. 2.28% 1,892,413 $47.0M New
EHAB Enhabit Inc. 0.83% 2,137,145 $17.1M No change

Portfolio Sells Q2 2025 → Q3 2025
TRMB Trimble Inc. Reduce -47.9% 7.44% −6.33
LW Lamb Weston Holdings Inc. Reduce -30.8% 14.08% −4.75
SPY SS SPDR S&P 500 ETF Trust-US Reduce -24.6% 12.47% −3.45
MKL Markel Group Inc. Reduce -2.7% 13.64% −1.55
WEX Wex Inc. Sold out 0.00% −1.21
MRCY Mercury Systems Inc. Reduce -11.8% 22.33% +4.06

Portfolio Buys Q2 2025 → Q3 2025
COO The Cooper Cos Inc. New 8.08% +8.08
FUN Six Flags Entertainment Corp. New 4.45% +4.45
ALKT Alkami Technology Inc. New 2.28% +2.28
FRPT Freshpet Inc. Add +4.1% 2.80% −0.64
RPD RAPID7 Inc. Add +13.5% 5.90% −0.75

All Filings

QuarterPositions13F Reported ValueTop Holdings
Q2 2026 10$1.9BMRCY, COO, SPY, LW, FISV
Q1 2026Amended 11$1.7BMRCY, COO, FISV, SPY, LW
Q4 2025 12$1.9BMRCY, COO, SPY, LW, MKL
Q3 2025 12$2.1BMRCY, LW, MKL, SPY, COO
Q2 2025 10$2.0BLW, MRCY, SPY, MKL, TRMB
Q1 2025 10$1.9BLW, SPY, MRCY, MKL, TRMB
Q4 2024 10$1.9BLW, TRMB, MRCY, SPY, MKL
Q3 2024 11$1.8BTRMB, SPY, MRCY, LW, THS
Q2 2024 12$1.7BFYBR, SPY, FIS, TRMB, MRCY
Q1 2024 10$1.8BSPY, FIS, TRMB, FYBR, MRCY