Winchester BancorpWSBK
13F holders, Q1 2026 (March 31)At the end of Q1 2026, 19 institutions reported holding Winchester Bancorp Inc. (WSBK) in their 13F filings, down 2 from Q4 2025. 0 opened new positions and 3 sold out. The largest holders were Mangrove Partners Im, LLC ($2.4M), Vanguard Capital Management LLC ($2.3M) and Northstar Financial Companies, Inc. ($889K). 2 famous investors held it, including Jim Simons / Peter Brown (0.0% of Renaissance Technologies's portfolio) and Israel Englander (0.0% of Millennium Management's portfolio).
- Company
- Winchester Bancorp Inc.
- CUSIP
- 97269D103
- Latest filing quarter
- Q2 2026
History
Number of 13F holders
Total Exit/New Position Q4 2025 → Q1 2026
| Institutions | Total Value | |
|---|---|---|
| New Positions | 0 | $0 |
| Exits | 3 | $222K |
All 13F filers, Q4 2025 → Q1 2026: 4,663 shares bought and 157,748 shares sold, net −153,085 shares. Counts holders who added, trimmed, opened or closed a position; split-adjusted.
Ownership 19 holders
| Mangrove Partners Im, LLC | 0.19% | No change | 186,201 | $2.4M |
| Vanguard Capital Management LLC | 0.00% | — | 181,513 | $2.3M |
| Northstar Financial Companies, Inc. | 0.71% | No change | 70,000 | $889K |
| Integrated Wealth Concepts LLC | 0.01% | No change | 57,000 | $724K |
| Oppenheimer & Close, LLC | 0.40% | No change | 50,000 | $635K |
| Renaissance Technologies | 0.00% | Add +17.0% | 31,000 | $394K |
| M3F, Inc. | 0.08% | Reduce -82.9% | 24,586 | $312K |
| Vanguard Fiduciary Trust Co. | 0.00% | — | 22,562 | $287K |
| Alliancebernstein L.P. | 0.00% | No change | 24,656 | $258K |
| Raymond James Financial Inc. | 0.00% | No change | 20,000 | $254K |
| Steward Partners Investment Advisory, LLC | 0.00% | No change | 19,127 | $243K |
| EagleClaw Capital Managment, LLC | 0.03% | No change | 16,000 | $203K |
| LPL Financial LLC | 0.00% | No change | 15,500 | $197K |
| Geode Capital Management, LLC | 0.00% | Reduce -47.5% | 13,920 | $177K |
| Millennium Management | 0.00% | Reduce -28.2% | 11,543 | $147K |
| Morgan Stanley | 0.00% | No change | 4,000 | $51K |
| Eastern Bank | 0.00% | No change | 2,500 | $32K |
| Tower Research Capital LLC (TRC) | 0.00% | Add +15.3% | 294 | $4K |
| UBS Group AG | 0.00% | Add +4200.0% | 129 | $2K |
"% of holder's portfolio" is WSBK's weight in each manager's 13F, not the share of Winchester Bancorp Inc. the manager owns.