JANA Partners Management, LP

Hedge Fund • Activist

JANA Partners Management, LP is an Activist Hedge Fund based in New York, NY led by Barry Stuart Rosenstein, reporting $2.4B in AUM as of Q3 2025 with 97% concentrated in top 10 holdings and 22% allocation to MRCY.

FounderBarry Stuart Rosenstein

Portfolio Value: $2.1B
Positions: 12
Top Holding: MRCY at 22.33%
Last Reported: Q3 2025

Address888 Seventh Avenue, 24th Floor, New York, NY, 10106, United States

Top Holdings

Largest long holdings in JANA Partners Management, LP's portfolio (96.9% of total portfolio)

See all holdings

GthenH

Holding	Sector	Position	Weight	Traded	Ownership	Owned Since
1 Mercury Systems MRCY	Aerospace & Defense Industrials	$461.3M	22.33%	-$61.5M Sold	9.93% 6.0M shares	Q3 2023 Held for 2y 2m
2 Lamb Weston LW	Packaged Foods Consumer Defensive	$290.9M	14.08%	-$129.1M Sold	3.59% 5.0M shares	Q3 2024 Held for 1y 2m
3 Markel MKL	Insurance - Property & Casualty Financial Services	$281.8M	13.64%	-$7.7M Sold	1.17% 147.4K shares	Q4 2024 Held for 11 months
4 SPDR S&P 500 ETF Trust SPY	ETF ETF	$257.6M	12.47%	-$84.2M Sold	— 386.6K shares	Q3 2023 Held for 2y 2m
5 The Cooper Companies, Inc. COO	Medical - Instruments & Supplies Healthcare	$166.9M	8.08%	+$166.9M New	1.22% 2.4M shares	Q3 2025 Held for 2 months
6 Trimble Inc. TRMB	Hardware, Equipment & Parts Technology	$153.6M	7.44%	-$141.1M Sold	0.79% 1.9M shares	Q4 2023 Held for 1y 11m
7 Rapid7 RPD	Software - Infrastructure Technology	$121.9M	5.90%	+$14.5M Bought	10.04% 6.5M shares	Q2 2024 Held for 1y 5m
8 Treehouse Foods THS	Packaged Foods Consumer Defensive	$117.6M	5.70%	—	11.53% 5.8M shares	Q3 2023 Held for 2y 2m
9 Six Flags Entertainment FUN	Leisure Consumer Cyclical	$92.0M	4.45%	+$92.0M New	4.00% 4.0M shares	Q3 2025 Held for 2 months
10 Freshpet FRPT	Packaged Foods Consumer Defensive	$57.8M	2.80%	+$2.3M Bought	2.15% 1.0M shares	Q1 2025 Held for 8 months

See all holdings

GthenH

Changes

Portfolio activity, position movements, and quarter-over-quarter changes in JANA Partners Management, LP's latest filing

See all changes

GthenC

Market Value

$2.1B

Prior: $2.0B

Q/Q Change

+3.74%

+$74.4M

New Purchases

3 stocks

$305.9M

Added To

2 stocks

+$16.8M

Sold Out Of

1 stocks

$24.1M

Reduced Holdings

5 stocks

-$423.5M

Increased Positions

Position	Shares Δ	Change
1 The Cooper Companies, Inc. COO	New	0 → 2.4M +$166.9M
2 Six Flags Entertainment FUN	New	0 → 4.0M +$92.0M
3 Alkami Technology, Inc. ALKT	New	0 → 1.9M +$47.0M
4 Rapid7 RPD	+13.48%	5.7M → 6.5M +$14.5M
5 Freshpet FRPT	+4.11%	1.0M → 1.0M +$2.3M

Decreased Positions

Position	Shares Δ	Change
1 WEX WEX	Sold	164.0K → 0 −$24.1M
2 Trimble Inc. TRMB	-47.87%	3.6M → 1.9M −$141.1M
3 Lamb Weston LW	-30.75%	7.2M → 5.0M −$129.1M
4 SPDR S&P 500 ETF Trust SPY	-24.64%	513.1K → 386.6K −$84.2M
5 Mercury Systems MRCY	-11.76%	6.8M → 6.0M −$61.5M