X0508 4 2025-05-05 0002047235 Winchester Bancorp, Inc./MD/ WSBK 0001602704 Carroll John A 661 MAIN STREET WINCHESTER MA 01890 1 1 President & CEO 0 Common Stock 2025-05-05 4 P 0 600 9.60 A 600 I By Trust Common Stock 2025-05-05 4 P 0 2222 9.7289 A 2822 I By Trust Common Stock 2025-05-05 4 P 0 4000 9.7387 A 6822 I By Trust Common Stock 2025-05-05 4 P 0 1652 9.7467 A 8474 I By Trust Common Stock 2025-05-05 4 P 0 4466 9.75 A 12940 I By Trust Common Stock 2025-05-05 4 P 0 2771 9.7789 A 15711 I By Trust Common Stock 2025-05-05 4 P 0 644 9.79 A 16355 I By Trust Common Stock 2025-05-05 4 P 0 5073 9.79890 A 21428 I By Trust Common Stock 2025-05-05 4 P 0 825 9.80 A 22253 I By Trust Common Stock 2025-05-05 4 P 0 2747 9.822 A 25000 I By Trust Common Stock 25000 D Common Stock 1000 I By Daughter /s/ Edward A. Quint, pursuant to power of attorney 2025-05-06