Winchester Bancorp, Inc.
WSBK- Exchange
- Nasdaq
- Industry
- Savings Institutions, Not Federally Chartered
- SEC CIK
- 0002047235
No open-market purchases or sales by Winchester Bancorp, Inc. insiders were filed in the last 90 days; 21 institutions reported holding it in 13F filings for Q2 2026, worth $9.96M in total; no superinvestor holds it.
13F holders, Q3 2025
Institutional positions in Winchester Bancorp, Inc. as of Sep 30, 2025. Investment managers with $100 million or more in US stocks report their long positions on Form 13F within 45 days after each quarter ends. How 13F works
- Institutional holders
- 22
- +4 vs. Q2 2025
- Shares held
- 708.3K
- +88.0K (+14.2%) vs. Q2 2025
- Total value
- $6.77M
- +$1.22M (+21.9%) vs. Q2 2025
- New holders
- 4
- 5 more added
- Sold out
- 0
- 7 more reduced
Compare with Q2 2025: new holders, sold out and not filed yet
Holders and value by quarter
Institutions reporting WSBK on Form 13F each quarter since Q1 2021, and the total value they reported. Values are as of each quarter end, so they also move with the share price.
| Quarter | Holders | Value |
|---|---|---|
| Q2 2026 | 21 | $9.96M |
| Q1 2026 | 19 | $9.48M |
| Q4 2025 | 21 | $8.06M |
| Q3 2025 | 22 | $6.77M |
| Q2 2025 | 18 | $5.55M |
| Q1 2025 | 0 | $0 |
| Q4 2024 | 0 | $0 |
| Q3 2024 | 0 | $0 |
| Q2 2024 | 0 | $0 |
| Q1 2024 | 0 | $0 |
| Q4 2023 | 0 | $0 |
| Q3 2023 | 0 | $0 |
| Q2 2023 | 0 | $0 |
| Q1 2023 | 0 | $0 |
| Q4 2022 | 0 | $0 |
| Q3 2022 | 0 | $0 |
| Q2 2022 | 0 | $0 |
| Q1 2022 | 0 | $0 |
| Q4 2021 | 0 | $0 |
| Q3 2021 | 0 | $0 |
| Q2 2021 | 0 | $0 |
| Q1 2021 | 0 | $0 |
Institutions, Q3 2025
Shares, value and share of portfolio for each institution holding Winchester Bancorp, Inc.; share changes are against Q2 2025.
| Institution | Shares | Value | % of portfolio | Change in shares | Action |
|---|---|---|---|---|---|
| Mangrove Partners | 186,949 | $1.79M | 0.15% | +17,851+10.6% | Added |
| M3F, Inc. | 82,552 | $788.0K | 0.22% | +23,229+39.2% | Added |
| Northstar Financial Companies, Inc. | 70,000 | $668.5K | 0.62% | +70,000 | New |
| Vanguard Group Inc | 69,167 | $663.3K | 0.00% | +185+0.3% | Added |
| Integrated Wealth Concepts LLC | 55,000 | $525.3K | 0.00% | 00.0% | Unchanged |
| Oppenheimer & Close, LLC | 50,000 | $477.5K | 0.32% | 00.0% | Unchanged |
| Citadel Advisors LLC | 26,438 | $253.5K | 0.00% | −15,491−36.9% | Reduced |
| Stilwell Value LLC | 25,000 | $238.8K | 0.11% | 00.0% | Unchanged |
| Geode Capital Management, LLC | 23,896 | $229.2K | 0.00% | +2,904+13.8% | Added |
| Raymond James Financial Inc | 20,000 | $191.0K | 0.00% | 00.0% | Unchanged |
| Millennium Management LLC | 18,947 | $181.7K | 0.00% | −4,324−18.6% | Reduced |
| EagleClaw Capital Managment, LLC | 16,000 | $152.8K | 0.02% | 00.0% | Unchanged |
| LPL Financial LLC | 15,500 | $148.0K | 0.00% | 00.0% | Unchanged |
| Lynch & Associates | 13,183 | $125.9K | 0.02% | −5,000−27.5% | Reduced |
| Steward Partners Investment Advisory, LLC | 10,750 | $102.7K | 0.00% | +8,250+330.0% | Added |
| Benin Management CORP | 10,000 | $95.5K | 0.02% | −500−4.8% | Reduced |
| UBS Group AG | 7,801 | $74.5K | 0.00% | −5,305−40.5% | Reduced |
| Morgan Stanley | 4,000 | $38.2K | 0.00% | +4,000 | New |
| Eastern Bank | 2,500 | $23.9K | 0.00% | +2,500 | New |
| Tower Research Capital LLC (TRC) | 355 | $3.39K | 0.00% | −286−44.6% | Reduced |
| Bank of America Corp | 225 | $2.15K | 0.00% | −9,986−97.8% | Reduced |
| Citigroup Inc | 1 | $10 | 0.00% | +1 | New |