Water Island Capital LLC

In its 13F for Q1 2026 (holdings as of March 31, 2026, filed May 15, 2026), Water Island Capital LLC reported 77 stock positions worth $710.8 million. Its top holding was Electronic Arts (EA) at 7.2% of the portfolio, followed by Janus Henderson (JHG, 6.7%) and Warner Bros Discovery (WBD, 6.2%). Compared with Q4 2025, it opened 51 new positions, sold out of 34, added to 17 and reduced 9. The biggest buy was a new position in Penumbra (PEN) and the biggest sale an exit from Cyberark Software Ltd./Israel (CYBR).

Most Recent 13F
Q2 2026
Location
NEW YORK, NY
CIK
0001222765
Portfolio Value
$710.8M (Q1 2026)
SEC Filing
0001222765-26-000007 ↗ filed May 15, 2026

Holdings Value

0$200.0M$400.0M$600.0M$800.0M$1.0B Q1 2024: $858.9M Q1 2024 Q2 2024: $899.0M Q2 2024 Q3 2024: $914.1M Q3 2024 Q4 2024: $762.7M Q4 2024 Q1 2025: $526.6M Q1 2025 Q2 2025: $517.5M Q2 2025 Q3 2025: $641.5M Q3 2025 Q4 2025: $760.3M Q4 2025 Q1 2026: $710.8M $710.8M Q1 2026 Q2 2026: $902.1M Q2 2026

Holdings 77 stocks · $710.8M
EA Electronic Arts Inc. 7.17% 249,888 $50.9M Add +38.2%
JHG Janus Henderson Group PLC 6.67% 922,277 $47.4M Add +42.4%
WBD Warner Bros Discovery Inc. 6.25% 1,617,020 $44.4M Add +41.9%
HOLX Hologic Inc. 5.96% 560,045 $42.3M Add +19.7%
TXNM TXNM Energy Inc. 5.55% 674,867 $39.5M Add +17.1%
PEN Penumbra Inc. 5.55% 120,095 $39.4M New
GTLS Chart Industries Inc. 5.52% 189,939 $39.3M Add +0.9%
NSC Norfolk Southern Corp. 5.41% 134,051 $38.5M Add +3.9%
MASI Masimo Corp. 4.86% 194,197 $34.5M New
WBS Webster Financial Corp. 4.06% 415,823 $28.9M New
TPH Tri Pointe Homes Inc. 3.53% 536,367 $25.1M New
NSA National Storage Affiliates 3.06% 576,224 $21.7M New
GLDD Great Lakes Dredge & Dock Co. 3.02% 1,263,580 $21.5M New
ACLX Arcellx Inc. 2.96% 183,409 $21.1M New
DAWN Day One Biopharmaceuticals I 2.85% 944,247 $20.2M New
DBRG Digitalbridge Group Inc. 2.82% 1,299,051 $20.0M Add +39.8%
STEL Stellar Bancorp Inc. 2.22% 431,231 $15.8M New
EHAB Enhabit Inc. 1.95% 984,611 $13.9M New
SLAB Silicon Laboratories Inc. 1.71% 58,417 $12.2M New
KVUE Kenvue Inc. 1.70% 700,600 $12.1M Add +1.5%
VRE Veris Residential Inc. 1.59% 597,390 $11.3M New
PKST Peakstone Realty Trust 1.48% 503,583 $10.5M New
TERN Terns Pharmaceuticals Inc. 1.40% 188,500 $9.9M New
KW Kennedy-Wilson Holdings Inc. 1.26% 825,652 $8.9M New
ZIM Zim Integrated Shipping Serv 1.23% 331,800 $8.7M New
UNF Unifirst Corp. 0.91% 25,743 $6.5M New
AXTA Axalta Coating Systems Ltd. 0.81% 206,902 $5.7M Add +0.6%
APLS Apellis Pharmaceuticals Inc. 0.68% 120,500 $4.8M New
AL Sumisho Air Lease Corp. filed as AIR LEASE CORP 0.67% 73,131 $4.7M Reduce -75.5%
AES AES Corp. 0.37% 185,833 $2.6M New
CWAN Clearwater Analytics HDS-A 0.36% 109,589 $2.6M Reduce -87.5%
SEE Sealed Air Corp. 0.33% 56,071 $2.4M Reduce -90.0%
AAUC Allied Gold Corp. 0.32% 72,785 $2.3M New
OS Onestream Inc. 0.31% 91,120 $2.2M New
BHF Brighthouse Financial Inc. 0.28% 33,490 $2.0M Add +16.1%
NATL NCR Atleos Corp. 0.24% 38,939 $1.7M New
SEM Select Medical Holdings Corp. 0.24% 103,467 $1.7M New
THR Thermon Group Holdings Inc. 0.23% 32,987 $1.7M New
SNCY Sun Country Airlines Holding filed as SUN CTRY AIRLS HLDGS INC 0.23% 98,859 $1.6M New
CNTA Centessa Pharmaceuticals Ltd. 0.23% 41,000 $1.6M New
CSGS CSG Systems Intl Inc. 0.23% 20,223 $1.6M Reduce -86.6%
SEMR Semrush Holdings Inc. Class A 0.22% 133,872 $1.6M Reduce -78.7%
FOLD Amicus Therapeutics Inc. 0.21% 104,066 $1.5M Reduce -85.3%
BA The Boeing Co. 0.20% 7,234 $1.4M New
STKL Sunopta Inc. 0.18% 196,514 $1.3M New
PRA Proassurance Corp. 0.18% 51,103 $1.3M Add +8.8%
CTLP Cantaloupe Inc. 0.16% 107,867 $1.2M Reduce -18.1%
CCO Clear Channel Outdoor Holdin 0.16% 478,517 $1.1M New
IHS Ihs Holding Ltd. 0.16% 137,615 $1.1M New
TALK Talkspace Inc. 0.16% 216,158 $1.1M New
MCW Mister Car Wash Inc. 0.15% 156,502 $1.1M New
DKS Dick's Sporting Goods Inc. 0.15% 5,348 $1.1M Add +386.2%
CTRA Coterra Energy Inc. 0.13% 27,292 $959K New
SKYT Skywater Technology Inc. 0.13% 34,536 $947K New
NWE Northwestern Energy Group Inc. 0.13% 13,838 $912K Reduce -3.3%
AMRX Amneal Pharmaceuticals Inc. 0.12% 68,400 $850K New
CZR Caesars Entertainment Inc. 0.11% 29,500 $780K New
UDMY Udemy Inc. 0.09% 139,335 $644K Add +2.5%
EL Estee Lauder Companies Class A filed as LAUDER ESTEE COS INC 0.08% 7,500 $538K New
PENN Penn Entertainment Inc. 0.07% 35,000 $526K New
CVGW Calavo Growers Inc. 0.07% 20,321 $524K New
IMXI International Money Express 0.07% 33,122 $523K Reduce -62.6%
NATH Nathan's Famous Inc. 0.07% 4,994 $503K New
ONTF ON24 Inc. 0.07% 60,364 $489K New
HTBK Heritage Commerce Corp. 0.07% 37,992 $474K Add +12.0%
BLFY Blue Foundry Bancorp 0.07% 35,658 $472K New
ECHO Echostar Corp. Class A 0.07% 4,000 $468K New
FFIC Flushing Financial Corp. 0.07% 30,161 $463K New
UAL United Airlines Holdings Inc. 0.06% 5,000 $460K New
DHIL Diamond Hill Investment Grp 0.06% 2,522 $434K Add +1.6%
FFWM First Foundation Inc. 0.06% 67,573 $399K Add +2.5%
ALK Alaska Air Group Inc. 0.05% 10,265 $378K New
PACB Pacific Biosciences of Calif 0.05% 272,040 $359K New
VCTR Victory Capital Holding - A 0.05% 5,120 $335K New
VKTX Viking Therapeutics Inc. 0.05% 10,280 $335K New
UPS United Parcel Service Class B 0.03% 2,520 $248K New
PYPL PayPal Holdings Inc. 0.03% 5,124 $232K New

Options reported separately and not counted above: ELECTRONIC ARTS INC puts ($30.5M), WARNER BROS DISCOVERY INC puts ($28.8M), DAY ONE BIOPHARMACEUTICALS I puts ($18.0M), KENVUE INC puts ($12.1M), TERNS PHARMACEUTICALS INC puts ($9.9M), SILICON LABORATORIES INC puts ($9.9M), ZIM INTEGRATED SHIPPING SERV puts ($8.7M), JANUS HENDERSON GROUP PLC puts ($7.9M), BANCO SANTANDER SA calls ($7.7M), AXALTA COATING SYS LTD puts ($5.4M), APELLIS PHARMACEUTICALS INC puts ($4.8M), CENTESSA PHARMACEUTICALS PLC puts ($1.6M).

Other holdings (9): bonds, preferreds, convertibles and warrants · $39.3M (not counted above)
SecurityClassShares / PrincipalValueChange
TXNM ENERGY INC (TXNM 5.75 06/01/54) NOTE 5.750% 6/0 · principal 6,000,000$8.1MAdd +100.0%
CSG SYSTEMS INTERNATIONA (CSGS 3.875 09/15/28) NOTE 3.875% 9/1 · principal 5,000,000$6.1MNo change
RAPID7 INC (RPD 0.25 03/15/27) NOTE 0.250% 3/1 · principal 5,501,530$4.9MNo change
BENTLEY SYSTEMS (BSY 0.375 07/01/27) NOTE 0.375% 7/0 · principal 5,000,000$4.7MNo change
NUTANIX INC (NTNX 0.5 12/15/29) NOTE 0.500%12/1 · principal 5,000,000$4.5MAdd +42.9%
REDFIN CORP (RDFN 0.5 04/01/27) NOTE 0.500% 4/0 · principal 4,500,000$4.3MNo change
HALOZYME THERAPEUTICS IN (HALO 0.25 03/01/27) NOTE 0.250% 3/0 · principal 3,000,000$3.1MNo change
VARONIS SYSTEM INC (VRNS 1 09/15/29) NOTE 1.000% 9/1 · principal 3,000,000$2.6MNo change
GLADSTONE CAPITAL CORP (GLAD 5.875 10/01/30) NOTE 5.875%10/0 · principal 1,000,000$968KReduce -50.0%

Total filed on the 13F, all lines: $750.1M.

Portfolio Sells Q4 2025 → Q1 2026
CYBR Cyberark Software Ltd./Israel Sold out 0.00% −5.08
EXAS Exact Sciences Corp. Sold out 0.00% −4.68
CMA Comerica Inc. Sold out 0.00% −4.55
CDTX Cidara Therapeutics Inc. Sold out 0.00% −4.38
AVDL Avadel Pharmaceuticals Ltd. Sold out 0.00% −3.08
TGNA Tegna Inc. Sold out 0.00% −3.01
AHL Aspen Insurance Holdings Class A Sold out 0.00% −2.79
SEE Sealed Air Corp. Reduce -90.0% 0.33% −2.72
SNV Synovus Financial Corp. Sold out 0.00% −2.66
CFLT Confluent Inc. Class A Sold out 0.00% −2.55
CWAN Clearwater Analytics HDS-A Reduce -87.5% 0.36% −2.41
AL Sumisho Air Lease Corp. Reduce -75.5% 0.67% −1.85
JAMF Jamf Holding Corp. Sold out 0.00% −1.69
CADE Cadence Bank Sold out 0.00% −1.68
HI Hillenbrand Inc. Sold out 0.00% −1.66
PLYM Plymouth Industrial REIT Inc. Sold out 0.00% −1.61
RNAM Avidity Biosciences Inc. Sold out 0.00% −1.60
CSGS CSG Systems Intl Inc. Reduce -86.6% 0.23% −1.29
DVAX Dynavax Technologies Corp. Sold out 0.00% −1.23
QRVO Qorvo Inc. Sold out 0.00% −1.22
FRGE Forge Global Holdings Inc. Sold out 0.00% −1.16
FOLD Amicus Therapeutics Inc. Reduce -85.3% 0.21% −1.11
ATXS Astria Therapeutics Inc. Sold out 0.00% −1.06
HOUS Anywhere Real Estate Inc. Sold out 0.00% −0.83
SEMR Semrush Holdings Inc. Class A Reduce -78.7% 0.22% −0.76
ALEX Alexander & Baldwin Inc. Sold out 0.00% −0.71
EB Eventbrite Inc. Class A Sold out 0.00% −0.58
DAY Dayforce Inc. Sold out 0.00% −0.43
THS Treehouse Foods Inc. Sold out 0.00% −0.31
NGD New Gold Inc. Sold out 0.00% −0.26
REVG Rev Group Inc. Sold out 0.00% −0.25
STAA Staar Surgical Co. Sold out 0.00% −0.21
WTRG Essential Utilities Inc. Sold out 0.00% −0.18
DENN Denny's Corp. Sold out 0.00% −0.17
MOFG Midwestone Financial Group I Sold out 0.00% −0.11
IMXI International Money Express Reduce -62.6% 0.07% −0.11
ZEUS Olympic Steel Inc. Sold out 0.00% −0.09
SHCO Soho House & Co. Inc. Sold out 0.00% −0.08
CIO City Office REIT Inc. Sold out 0.00% −0.06
TRUE Truecar Inc. Sold out 0.00% −0.05
FSFG First Savings Financial Grp Sold out 0.00% −0.04
CTLP Cantaloupe Inc. Reduce -18.1% 0.16% −0.02
NWE Northwestern Energy Group Inc. Reduce -3.3% 0.13% +0.01

Portfolio Buys Q4 2025 → Q1 2026
PEN Penumbra Inc. New 5.55% +5.55
MASI Masimo Corp. New 4.86% +4.86
WBS Webster Financial Corp. New 4.06% +4.06
TPH Tri Pointe Homes Inc. New 3.53% +3.53
NSA National Storage Affiliates New 3.06% +3.06
GLDD Great Lakes Dredge & Dock Co. New 3.02% +3.02
ACLX Arcellx Inc. New 2.96% +2.96
DAWN Day One Biopharmaceuticals I New 2.85% +2.85
JHG Janus Henderson Group PLC Add +42.4% 6.67% +2.61
EA Electronic Arts Inc. Add +38.2% 7.17% +2.31
STEL Stellar Bancorp Inc. New 2.22% +2.22
EHAB Enhabit Inc. New 1.95% +1.95
WBD Warner Bros Discovery Inc. Add +41.9% 6.25% +1.93
SLAB Silicon Laboratories Inc. New 1.71% +1.71
VRE Veris Residential Inc. New 1.59% +1.59
PKST Peakstone Realty Trust New 1.48% +1.48
TERN Terns Pharmaceuticals Inc. New 1.40% +1.40
HOLX Hologic Inc. Add +19.7% 5.96% +1.37
KW Kennedy-Wilson Holdings Inc. New 1.26% +1.26
ZIM Zim Integrated Shipping Serv New 1.23% +1.23
TXNM TXNM Energy Inc. Add +17.1% 5.55% +1.09
DBRG Digitalbridge Group Inc. Add +39.8% 2.82% +0.94
UNF Unifirst Corp. New 0.91% +0.91
APLS Apellis Pharmaceuticals Inc. New 0.68% +0.68
NSC Norfolk Southern Corp. Add +3.9% 5.41% +0.51
GTLS Chart Industries Inc. Add +0.9% 5.52% +0.42
AES AES Corp. New 0.37% +0.37
AAUC Allied Gold Corp. New 0.32% +0.32
OS Onestream Inc. New 0.31% +0.31
NATL NCR Atleos Corp. New 0.24% +0.24
SEM Select Medical Holdings Corp. New 0.24% +0.24
THR Thermon Group Holdings Inc. New 0.23% +0.23
SNCY Sun Country Airlines Holding New 0.23% +0.23
CNTA Centessa Pharmaceuticals Ltd. New 0.23% +0.23
BA The Boeing Co. New 0.20% +0.20
STKL Sunopta Inc. New 0.18% +0.18
CCO Clear Channel Outdoor Holdin New 0.16% +0.16
IHS Ihs Holding Ltd. New 0.16% +0.16
TALK Talkspace Inc. New 0.16% +0.16
MCW Mister Car Wash Inc. New 0.15% +0.15
CTRA Coterra Energy Inc. New 0.13% +0.13
KVUE Kenvue Inc. Add +1.5% 1.70% +0.13
SKYT Skywater Technology Inc. New 0.13% +0.13
DKS Dick's Sporting Goods Inc. Add +386.2% 0.15% +0.12
AMRX Amneal Pharmaceuticals Inc. New 0.12% +0.12
CZR Caesars Entertainment Inc. New 0.11% +0.11
EL Estee Lauder Companies Class A New 0.08% +0.08
PENN Penn Entertainment Inc. New 0.07% +0.07
CVGW Calavo Growers Inc. New 0.07% +0.07
NATH Nathan's Famous Inc. New 0.07% +0.07

Options Activity Q4 2025 → Q1 2026
ELECTRONIC ARTS INC put New 149,800 $30.5M
WARNER BROS DISCOVERY INC put Add +1005.9% 1,049,500 $28.8M
DAY ONE BIOPHARMACEUTICALS I put New 839,700 $18.0M
STATE STR SPDR S&P 500 ETF T call Sold out 25,000 $17.0Mbefore exit
CIDARA THERAPEUTICS INC put Sold out 76,900 $17.0Mbefore exit
TECK RESOURCES LTD put Sold out 292,100 $14.0Mbefore exit
AVIDITY BIOSCIENCES INC put Sold out 168,700 $12.2Mbefore exit
KENVUE INC put Add +0.8% 700,600 $12.1M
HILLENBRAND INC put Sold out 315,000 $10.0Mbefore exit
TERNS PHARMACEUTICALS INC put New 188,500 $9.9M
SILICON LABORATORIES INC put New 47,600 $9.9M
ZIM INTEGRATED SHIPPING SERV put New 331,800 $8.7M
JANUS HENDERSON GROUP PLC put Add +1185.8% 154,300 $7.9M
BANCO SANTANDER SA call New 681,700 $7.7M
AMICUS THERAPEUTICS INC call Sold out 451,000 $6.4Mbefore exit
AXALTA COATING SYS LTD put Add +190.6% 195,000 $5.4M
APELLIS PHARMACEUTICALS INC put New 120,500 $4.8M
HOLOGIC INC put Sold out 60,600 $4.5Mbefore exit
KIMBERLY-CLARK CORP call Sold out 42,200 $4.3Mbefore exit
CORE SCIENTIFIC INC NEW call Sold out 143,800 $2.1Mbefore exit
KENVUE INC call Sold out 118,400 $2.0Mbefore exit
CENTESSA PHARMACEUTICALS PLC put New 41,000 $1.6M
REALOGY HLDGS CORP call Sold out 71,100 $1.0Mbefore exit
REALOGY HLDGS CORP put Sold out 71,100 $1.0Mbefore exit

Calls and puts are listed by the shares they cover; their value is not part of the stock holdings above.

Notes & Other Activity Q4 2025 → Q1 2026
TXNM ENERGY INC (TXNM 5.75 06/01/54) NOTE 5.750% 6/0 · principal Add +100.0% 6,000,000 $8.1M
SPOTIFY USA INC (SPOT 0 03/15/26) NOTE 3/1 · principal Sold out 5,000,000 $5.7Mbefore exit
BOEING CO/THE (BA 6 10/15/27) DEP CONV PFD A Sold out 80,000 $5.5Mbefore exit
CONFLUENT INC (CFLT 0 01/15/27) NOTE 1/1 · principal Sold out 5,000,000 $4.9Mbefore exit
NUTANIX INC (NTNX 0.5 12/15/29) NOTE 0.500%12/1 · principal Add +42.9% 5,000,000 $4.5M
BLACKLINE INC (BL 0 03/15/26) NOTE 3/1 · principal Sold out 3,071,000 $3.0Mbefore exit
ITRON INC (ITRI 0 03/15/26) NOTE 3/1 · principal Sold out 2,500,000 $2.5Mbefore exit
EVOLENT HEALTH INC (EVH 3.5 12/01/29) NOTE 3.500%12/0 · principal Sold out 2,000,000 $1.3Mbefore exit
GLADSTONE CAPITAL CORP (GLAD 5.875 10/01/30) NOTE 5.875%10/0 · principal Reduce -50.0% 1,000,000 $968K

Bonds, preferreds, convertibles and warrants; not part of the stock holdings or percentages above.

All Filings

QuarterPositions13F Reported ValueTop Holdings
Q2 2026 67$902.1MTMHC, EA, GTLS, PEN, WBD
Q1 2026 77$710.8MEA, JHG, WBD, HOLX, TXNM
Q4 2025 60$760.3MGTLS, CYBR, NSC, EA, EXAS
Q3 2025 57$641.5MCYBR, NSC, VRNA, AVDX, INFA
Q2 2025 44$517.5MAMED, ANSS, JNPR, HES, SWTX
Q1 2025 49$526.6MAMED, HES, HEES, K, EVRI
Q4 2024 48$762.7MAMED, HES, K, HCP, EDR
Q3 2024 56$914.1MAMED, HES, K, AXONICS INC, SQSP
Q2 2024Amended 57$899.0MAMED, HES, AXONICS INC, HCP, ACI
Q1 2024Amended 41$858.9MPXD, HES, AMED, EVBG, AXONICS INC