Exhibit 99.1 Winchester Bancorp, Inc. Announces Results for the Quarter Ended September 30, 2025 Investor Contact John A. Carroll President and Chief Executive Officer IR@WinchesterSavings.com (781) 729-2130 WINCHESTER, MA, October 22, 2025 - Winchester Bancorp, Inc. (NASDAQ-WSBK) (the "Company"), the holding company for Winchester Savings Bank (the "Bank"), today announced its first quarter financial results. The Company reported net income of $962 thousand or$0.11 cents per common share compared to a net ...