Winchester Bancorp, Inc. (WSBK) Ownership
WSBK ownership summary
as of October 18, 2026- Institutions
- 8.4% of shares outstanding
- Insiders
- 59.30% of shares outstanding
- Shares outstanding
- 9.0M
- Float
- 3.8M shares available to trade
- Short interest
- 0.59% 21K shares short
- Days to cover
- 2.68 short interest up 67.0% vs prior month
- Institutions 8.35%
- Insiders 59.30%
- Other investors 32.34%
WSBK top institutional holders
20 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | Mangrove Partners | 2.08% | 186K | $2.4M | — | June 30, 2026 |
| 2 | Vanguard Capital Management, LLC | 2.00% | 179K | $2.3M | −2,572 (−1.4%) | June 30, 2026 |
| 3 | Northstar Financial Companies, INC. | 0.78% | 70K | $904,400 | — | June 30, 2026 |
| 4 | Integrated Wealth Concepts LLC | 0.64% | 57K | $736,440 | — | June 30, 2026 |
| 5 | Oppenheimer & Close Inc | 0.56% | 50K | $646,000 | — | June 30, 2026 |
| 6 | Renaissance Technologies Corp | 0.35% | 31K | $405,688 | +400 (+1.3%) | June 30, 2026 |
| 7 | Geode Capital Management, LLC | 0.32% | 29K | $375,158 | +15,117 (+108.6%) | June 30, 2026 |
| 8 | RFG - Bristol Wealth Advisors, LLC | 0.31% | 28K | $355,300 | +17,342 (+170.7%) | September 30, 2026 |
| 9 | AllianceBernstein L.P. | 0.28% | 25K | $318,556 | — | June 30, 2026 |
| 10 | Vanguard Fiduciary Trust Co | 0.25% | 23K | $293,387 | +146 (+0.6%) | June 30, 2026 |
| 11 | Steward Partners Investment Advisory, LLC | 0.21% | 19K | $247,121 | — | June 30, 2026 |
| 12 | Eagleclaw Capital Management LLC | 0.18% | 16K | $206,720 | — | June 30, 2026 |
| 13 | LPL Financial Corp | 0.17% | 16K | $200,260 | — | June 30, 2026 |
| 14 | BlackRock Inc | 0.16% | 14K | $183,490 | +14,202 (0.0%) | June 30, 2026 |
| 15 | Sachetta LLC | 0.09% | 8,000 | $103,360 | +8,000 (0.0%) | June 30, 2026 |
| 16 | Eastern Bank | 0.04% | 4,000 | $51,680 | +1,500 (+60.0%) | June 30, 2026 |
| 17 | Royal Bank of Canada | 0.02% | 2,000 | $25,840 | +2,000 (0.0%) | June 30, 2026 |
| 18 | Tower Research Capital LLC | <0.01% | 157 | $2,028 | −137 (−46.6%) | June 30, 2026 |
| 19 | UBS Group AG | <0.01% | 18 | $233 | −111 (−86.0%) | June 30, 2026 |
| 20 | Advisor Group Holdings, Inc. | <0.01% | 16 | $207 | +16 (0.0%) | June 30, 2026 |
Value at the latest close. Change = shares bought or sold in the latest quarterly filing (13F). In the top 20, 9 holders added 59K shares and 3 cut 2,820.
WSBK top mutual fund and ETF holders
8 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | Vanguard MStar Total Stk Mkt Idx Invest | 1.47% | 132K | $1.7M | — | August 31, 2026 |
| 2 | Fidelity Extended Market Index | 0.17% | 15K | $195,002 | −81 (−0.5%) | August 31, 2026 |
| 3 | iShares Micro-Cap ETF | 0.14% | 13K | $164,614 | −88 (−0.7%) | September 30, 2026 |
| 4 | Fidelity Series Total Market Index | 0.07% | 6,073 | $78,463 | — | August 31, 2026 |
| 5 | Vanguard Balanced Index Inv | 0.03% | 2,273 | $29,367 | — | August 31, 2026 |
| 6 | Fidelity Total Market Index | 0.01% | 1,145 | $14,793 | +221 (+23.9%) | August 31, 2026 |
| 7 | 1290 VT Micro Cap K | 0.01% | 857 | $11,072 | — | August 31, 2026 |
| 8 | Victory Extended Market Index | <0.01% | 419 | $5,413 | +419 (0.0%) | June 30, 2026 |
Funds report holdings monthly or quarterly; dates differ by fund.
WSBK insider transactions
latest 2| Date | Name | Transaction | Price | Shares | Value |
|---|---|---|---|---|---|
| 2025-05-07 | William Preston Hood | Buy | $9.68 | 10,000 | $96,800 |
| 2025-05-05 | John A Carroll | Buy | $9.77 | 25,000 | $244,250 |
Reported trades by company officers, directors and other filers (including disclosures by members of Congress where EODHD lists them). "—" where the filing gives no share count.
WSBK shares outstanding
Year-end shares outstanding, adjusted for splits.
Who owns WSBK
Institutional investors own 8.4% of Winchester Bancorp's shares and insiders 59.30%. The largest holder is Mangrove Partners with 2.08% of the shares (186K), as of June 30, 2026. Among the top 20 institutions, 9 added shares and 3 reduced their stake in the latest filings. Short interest is 0.59% of the float, or 2.68 days of average trading volume. The share count fell 5.1% since 2023.
Related: WSBK key metrics. See the WSBK stock overview for the latest quote and news.
WSBK ownership FAQ
Who owns the most Winchester Bancorp stock?
The largest shareholders of Winchester Bancorp are Mangrove Partners (2.08%), Vanguard Capital Management, LLC (2.00%), Northstar Financial Companies, INC. (0.78%), Integrated Wealth Concepts LLC (0.64%), Oppenheimer & Close Inc (0.56%).
What percentage of Winchester Bancorp is owned by institutions?
Institutions hold 8.4% of Winchester Bancorp's shares outstanding; insiders hold 59.30%.
Which funds own Winchester Bancorp?
The largest fund holders of Winchester Bancorp are Vanguard MStar Total Stk Mkt Idx Invest (1.47%), Fidelity Extended Market Index (0.17%), iShares Micro-Cap ETF (0.14%), Fidelity Series Total Market Index (0.07%), Vanguard Balanced Index Inv (0.03%).
What is Winchester Bancorp's short interest?
21K shares of Winchester Bancorp were sold short, 0.59% of the float; at the average daily volume it would take 2.68 days to cover.
Are insiders buying or selling Winchester Bancorp?
Of the latest 2 reported insider transactions in Winchester Bancorp (since May 5, 2025), 2 were purchases and 0 were sales.
How many shares of Winchester Bancorp are outstanding?
Winchester Bancorp has 9.0M shares outstanding, of which 3.8M are in the public float.