23 institutions reported holding $10.3M of WINCHESTER BANCORP INC (WSBK) in SEC 13F filings for 2026-06-30. Largest institutional holders: VANGUARD GROUP INC ($2.6M), MANGROVE PARTNERS IM, LLC ($2.4M), Integrated Wealth Concepts LLC ($1.1M), Northstar Financial Companies, Inc. ($919,800), Oppenheimer & Close, LLC ($657,000). Source: SEC Form 13F.
| Rank | Institution | Value | Shares | Change |
|---|---|---|---|---|
| 1 | VANGUARD GROUP INC | $2.6M | 201,649 | Trimmed |
| 2 | MANGROVE PARTNERS IM, LLC | $2.4M | 186,201 | Hold |
| 3 | Integrated Wealth Concepts LLC | $1.1M | 82,000 | Added |
| 4 | Northstar Financial Companies, Inc. | $919,800 | 70,000 | Hold |
| 5 | Oppenheimer & Close, LLC | $657,000 | 50,000 | Hold |
| 6 | RENAISSANCE TECHNOLOGIES LLC | $412,596 | 31,400 | Added |
| 7 | GEODE CAPITAL MANAGEMENT, LLC | $381,809 | 29,037 | Added |
| 8 | ALLIANCEBERNSTEIN L.P. | $313,131 | 24,656 | Hold |
| 9 | RAYMOND JAMES FINANCIAL INC | $262,800 | 20,000 | Hold |
| 10 | Steward Partners Investment Advisory, LLC | $251,329 | 19,127 | Hold |
| 11 | EagleClaw Capital Managment, LLC | $210,240 | 16,000 | Hold |
| 12 | LPL Financial LLC | $203,670 | 15,500 | Hold |
| 13 | BlackRock, Inc. | $186,614 | 14,202 | New |
| 14 | RFG - Bristol Wealth Advisors, LLC | $133,476 | 10,158 | New |
| 15 | Sachetta, LLC | $105,120 | 8,000 | New |
| 16 | EASTERN BANK | $52,560 | 4,000 | Added |
| 17 | Royal Bank of Canada | $26,000 | 2,000 | New |
| 18 | Tower Research Capital LLC (TRC) | $2,063 | 157 | Trimmed |
| 19 | UBS Group AG | $237 | 18 | Trimmed |
| 20 | OSAIC HOLDINGS, INC. | $210 | 16 | New |
| 21 | MORGAN STANLEY | $0 | 0 | Exited |
| 22 | M3F, Inc. | $0 | 0 | Exited |
| 23 | MILLENNIUM MANAGEMENT LLC | $0 | 0 | Exited |
Source: SEC Form 13F filings · as of 2026-06-30