DOSSIER · 13F-HR · Q4 2025

WATER ISLAND CAPITAL LLC

WATER ISLAND's hedge fund based in New York, NY $928M in tracked AUM across 91 positions as of Q4 2025.

WI
WATER ISLAND·New York, NY·Hedge Fund
CIK 0001222765 · last filed Dec 31, 2025
Total AUM
$928M
10.4%
vs prior
Holdings
91
positions
Whale Score
50
50
tracked
Activity
no data
changes this Q
Top sector
Tech
27% weight
concentration
AI Analysis · Q4 2025 · Q4 2025
Portfolio Overview

Water Island Capital reports a $573.16 million long-equity portfolio as of 2025-09-30, down 18.4% from $701.99 million on 2025-06-30. The filing lists 60 holdings with very high turnover: 37 new positions and 37 sold positions versus the prior quarter, plus only 3 net stake increases and 2 reductions. The portfolio is highly concentrated: the top 10 holdings account for roughly $266.2M, or ~46.5% of the portfolio, and the largest single position (CyberArk) is $41.45M, or 7.2...

Quarter at a glance — Q4 2025

Position-change comparison pending.

No quarter-over-quarter changes available.

Top 10 holdings

By portfolio weight as of Q4 2025.

#HoldingValueSharesWeight
01
GTLS
Chart Industries Inc
$39M188K4.2%
02
M2682V108
CyberArk Software Ltd
$39M87K4.2%
03
NSC
Norfolk Southern Corp
$37M129K4.0%
04
EA
Electronic Arts Inc
$37M181K4.0%
05
EXAS
Exact Sciences Corp
$36M350K3.8%
06
HOLX
Hologic Inc
$35M468K3.8%
07
CMA
Comerica Inc
$35M398K3.7%
08
TXNM
TXNM Energy Inc
$34M576K3.7%
09
CDTX
Cidara Therapeutics Inc
$33M151K3.6%
10
WBD
Warner Bros Discovery Inc
$33M1.1M3.5%

Filing history

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