Institutional Manager · CIK 0001222765
WATER ISLAND CAPITAL LLC
NEW YORK, NY · File #028-10693
Latest AUM
$927.6M
Positions
91
Top-10 Concentration
41.7%
Filings
16
Portfolio Value Over Time
2024-03
2024-06
2024-09
2024-12
2025-03
2025-06
2025-09
2025-12
Biggest QoQ Changes
Ranked by conviction flow (share change × current price) so mark-to-market moves don't dominate. Price effect column shows how much of the $ change was just the stock moving.
| Action | Issuer | Ticker / CUSIP | Δ Shares | Flow ($) | Price Effect |
|---|---|---|---|---|---|
| NEW | Exact Sciences Corp | 30063P105 | +350,009 | +$35.5M | $0 |
| NEW | Hologic Inc | HOLX | +467,742 | +$34.8M | $0 |
| NEW | Comerica Inc | 200340107 | +398,037 | +$34.6M | $0 |
| NEW | Cidara Therapeutics Inc | 171757206 | +150,708 | +$33.3M | $0 |
| NEW | Warner Bros Discovery Inc | WBD | +1,139,634 | +$32.8M | $0 |
| EXITED | VERONA PHARMA PLC | 925050106 | -290,182 | -$31.0M | $0 |
| NEW | Janus Henderson Group PLC | JHG | +647,485 | +$30.8M | $0 |
| EXITED | AVIDXCHANGE HOLDINGS INC | 05368X102 | -2,882,867 | -$28.7M | $0 |
| EXITED | INFORMATICA INC | 45674M101 | -1,149,598 | -$28.6M | $0 |
| EXITED | VERITEX HLDGS INC | 923451108 | -815,698 | -$27.4M | $0 |
Sector Allocation
Filing History
- 13F HOLDINGS REPORTQ/E Dec 202591 pos · $927.6M
- 13F HOLDINGS REPORTQ/E Sep 202584 pos · $793.3M
- 13F HOLDINGS REPORTQ/E Jun 202576 pos · $702.0M
- 13F HOLDINGS REPORTQ/E Mar 202584 pos · $764.1M
- 13F HOLDINGS REPORTQ/E Dec 202478 pos · $925.7M
- 13F HOLDINGS REPORT (Amended)Q/E Sep 202461 pos · $961.8M
- 13F HOLDINGS REPORT (Amended)Q/E Sep 202476 pos · $1.17B
- 13F HOLDINGS REPORT (Amended)Q/E Sep 202458 pos · $1.01B
- 13F HOLDINGS REPORT (Amended)Q/E Sep 202481 pos · $1.12B
- 13F HOLDINGS REPORT (Amended)Q/E Sep 202475 pos · $1.27B
- 13F HOLDINGS REPORTQ/E Sep 202479 pos · $992.7M
- 13F HOLDINGS REPORT (Amended)Q/E Sep 202487 pos · $1.24B
- 13F HOLDINGS REPORT (Amended)Q/E Sep 202475 pos · $986.6M
- 13F HOLDINGS REPORTQ/E Jun 202471 pos · $943,004
- 13F HOLDINGS REPORTQ/E Mar 202459 pos · $883,660
- 13F HOLDINGS REPORTQ/E Dec 202381 pos · $1.1M
Top 20 Holdings — Dec 2025
| # | Issuer | Ticker | Shares | Value | % of Portfolio |
|---|---|---|---|---|---|
| 1 | Chart Industries Inc | 16115Q308 | 188,325 | $38.8M | 4.54% |
| 2 | CyberArk Software Ltd | M2682V108 | 86,648 | $38.7M | 4.52% |
| 3 | Norfolk Southern Corp | 655844108 | 129,043 | $37.3M | 4.36% |
| 4 | Electronic Arts Inc | EA | 180,838 | $37.0M | 4.32% |
| 5 | Exact Sciences Corp | 30063P105 | 350,009 | $35.5M | 4.16% |
| 6 | Hologic Inc | HOLX | 467,742 | $34.8M | 4.08% |
| 7 | Comerica Inc | 200340107 | 398,037 | $34.6M | 4.05% |
| 8 | TXNM Energy Inc | TXNM | 576,411 | $33.9M | 3.97% |
| 9 | Cidara Therapeutics Inc | 171757206 | 150,708 | $33.3M | 3.89% |
| 10 | Warner Bros Discovery Inc | WBD | 1,139,634 | $32.8M | 3.84% |
| 11 | Janus Henderson Group PLC | JHG | 647,485 | $30.8M | 3.60% |
| 12 | Avadel Pharmaceuticals PLC | G29687103 | 1,087,117 | $23.4M | 2.74% |
| 13 | Sealed Air Corp | SE | 559,237 | $23.2M | 2.71% |
| 14 | TEGNA Inc | 87901J105 | 1,179,885 | $22.9M | 2.68% |
| 15 | Aspen Insurance Holdings Ltd | AHL-PF | 572,685 | $21.2M | 2.49% |
| 16 | Clearwater Analytics Holdings | CWAN | 875,632 | $21.1M | 2.47% |
| 17 | Synovus Financial Corp | 87161C501 | 403,650 | $20.2M | 2.36% |
| 18 | Confluent Inc | 20717M103 | 640,113 | $19.4M | 2.26% |
| 19 | Air Lease Corp | AIIR | 298,440 | $19.2M | 2.24% |
| 20 | State Street SPDR S&P 500 ETF | SPY | 25,000 | $17.0M | 1.99% |