InsiderTrades

Form 4 for CBU COMMUNITY FINANCIAL SYSTEM, INC.

Accepted 2025-12-03 00:00:00 ET · period of report 2025-12-01 · accession 0000723188-25-000012 · SEC index · Original document

Summary rows

Aggregated the way they appear in lists: one row per insider, transaction code and security table.

X Filed Traded Ticker Insider Title Type Price Qty Owned ΔOwn Value
D 2025-12-03 2025-12-01 CBU Whipple John F. Dir M - OptEx — +1,370 8,506 +19% —
D 2025-12-03 2025-12-01 CBU Whipple John F. Dir M - OptEx — -1,370 5,707 -19% —

Purchase Sale Sale after option exercise All abbreviations

Every reported transaction

#TableSecurityDateCodeA/DSharesPriceOwned afterOwnExercise / expiryUnderlyingFootnotes
1 Common Common Stock 2025-12-01 M A 1,370 — 8,506.03 D — — (F1) On December 1, 2025, the reporting person's phantom stock units were settled for 1,370 shares of Community Financial System, Inc. common stock.
2 Derivative Phantom Stock (Deferred Compensation) 2025-12-01 M D 1,370 — 5,707.39 D — · — to — 1,370 Common Stock (F1) On December 1, 2025, the reporting person's phantom stock units were settled for 1,370 shares of Community Financial System, Inc. common stock. (F3) Includes 53.6874, 61.6877, 53.8395, and 59.5376 units of phantom stock acquired on January 10, 2025, April 10, 2025, July 10, 2025, and October 10, 2025, respectively, as dividend equivalents under the Plan. (F2) Each unit of phantom stock is the economic equivalent of one share of Community Financial System, Inc. common stock. The units of phantom stock relating to the Deferred Compensation Plan will be settled in Community Financial System, Inc. common stock at future dates selected by the reporting person.