Maureen A Gillan-Myer

Insider

First SEC filing: Oct. 5, 2021 · Latest: March 19, 2026

On this page

Insider at Companies where this person is a reporting insider.
Insider transactions Every share this person bought or sold, from Form 4 filings.
Derivatives Options and other derivative holdings reported by this person.
Initial holdings The stakes this person held when they first started reporting.

Insider at

CBU selling Dec. 29, 2025

Insider transactions

0 buys (P) 1 sells (S) Net: $-203,032 + 25 non-open-market transactions below last 12 months, based on the transactions shown below

Price change vs current quote, split-adjusted for corporate actions since the filing — not benchmarked, not annualized, not size-weighted

25 other filings hidden

Date	Ticker	Code	Shares	Price	Value	Owned after	Δ own	A/D	vs now
March 17, 2026	CBU	A	4,871	—	—	4,871 Direct	—	Acquired	(price as of 2026-08-21)
March 17, 2026	CBU	A	1,275	—	—	1,275 Direct	—	Acquired	(price as of 2026-08-21)
March 4, 2026	CBU	F	943	$59.87	$56,457	6,647 Direct	-12.42%	Disposed	6.1% (price as of 2026-08-21)
March 4, 2026	CBU	A	2,562	—	—	7,590 Direct	+50.95%	Acquired	(price as of 2026-08-21)
March 2, 2026	CBU	F	522	$60.55	$31,607	5,028 Direct	-9.41%	Disposed	4.9% (price as of 2026-08-21)
Dec. 29, 2025	CBU	S	3,450	$58.85	$203,032	0 Indirect	-100.00%	Disposed	7.9% (price as of 2026-08-21)
March 18, 2025	CBU	A	1,233	—	—	1,233 Direct	—	Acquired	(price as of 2026-08-21)
March 18, 2025	CBU	A	4,553	—	—	8,870 Direct	+105.47%	Acquired	(price as of 2026-08-21)
March 18, 2025	CBU	A	4,553	—	—	4,553 Direct	—	Acquired	(price as of 2026-08-21)
March 18, 2025	CBU	A	1,233	—	—	5,550 Direct	+28.56%	Acquired	(price as of 2026-08-21)
March 12, 2025	CBU	F	532	—	—	4,317 Direct	-10.97%	Disposed	(price as of 2026-08-21)
March 7, 2025	CBU	A	1,472	—	—	4,849 Direct	+43.59%	Acquired	(price as of 2026-08-21)
March 3, 2025	CBU	F	444	$63.29	$28,101	3,377 Direct	-11.62%	Disposed	0.3% (price as of 2026-08-21)
Oct. 1, 2024	CBU	F	177	$58.07	$10,278	3,821 Direct	-4.43%	Disposed	9.4% (price as of 2026-08-21)
March 19, 2024	CBU	A	4,987	—	—	4,987 Direct	—	Acquired	(price as of 2026-08-21)
March 19, 2024	CBU	A	1,391	—	—	3,998 Direct	+53.36%	Acquired	(price as of 2026-08-21)
March 1, 2024	CBU	F	218	$45.30	$9,875	2,607 Direct	-7.72%	Disposed	40.2% (price as of 2026-08-21)
Oct. 1, 2023	CBU	F	176	$42.21	$7,429	2,825 Direct	-5.86%	Disposed	50.4% (price as of 2026-08-21)
March 14, 2023	CBU	A	4,199	—	—	4,199 Direct	—	Acquired	(price as of 2026-08-21)
March 14, 2023	CBU	A	1,152	—	—	3,001 Direct	+62.30%	Acquired	(price as of 2026-08-21)
March 8, 2023	CBU	F	81	$61.05	$4,945	1,849 Direct	-4.20%	Disposed	4.0% (price as of 2026-08-21)
Oct. 3, 2022	CBU	F	203	$60.08	$12,196	1,930 Direct	-9.52%	Disposed	5.7% (price as of 2026-08-21)
March 15, 2022	CBU	A	2,676	—	—	2,676 Direct	—	Acquired	(price as of 2026-08-21)
March 15, 2022	CBU	A	2,676	—	—	2,676 Direct	—	Acquired	(price as of 2026-08-21)
March 15, 2022	CBU	A	666	—	—	2,133 Direct	+45.40%	Acquired	(price as of 2026-08-21)
Oct. 1, 2021	CBU	A	1,467	—	—	1,467 Direct	—	Acquired	(price as of 2026-08-21)

P = Open-market purchase · S = Sale · A = Grant/award · M = Option exercise · G = Gift · F = Tax withholding

Insider transactions are not a recommendation; sales are often driven by liquidity or tax reasons.

Derivative holdings (Form 4 Table II)

Options, RSUs and convertible securities reported on Form 4 Table II.

Date	Ticker	Security	Underlying	Exercise price	Expiration	Shares	A/D
March 17, 2026	CBU	Stock Option	Common Stock (4,871)	$56.64	March 17, 2036	4,871	Acquired
March 17, 2026	CBU	Restricted Stock Units	Common Stock (1,275)	—	—	1,275	Acquired
March 18, 2025	CBU	Stock Option	Common Stock (1,233)	$58.10	March 18, 2035	1,233	Acquired
March 18, 2025	CBU	Stock Option	Common Stock (4,553)	$58.10	March 18, 2035	4,553	Acquired
March 19, 2024	CBU	Stock Option	Common Stock (4,987)	$44.27	March 19, 2034	4,987	Acquired
March 14, 2023	CBU	Stock Option	Common Stock (4,199)	$54.06	March 14, 2033	4,199	Acquired
March 15, 2022	CBU	Stock Option	Common Stock (2,676)	—	March 15, 2032	2,676	Acquired
March 15, 2022	CBU	Stock Option	Common Stock (2,676)	$72.51	March 15, 2032	2,676	Acquired

Exercise/conversion price is blank when not applicable (e.g. RSUs).

Initial ownership (Form 3) 1 holding

Securities held when first becoming an insider, per SEC Form 3.

Date	Ticker	Security	Shares	Ownership
Oct. 5, 2021	CBU	Common Stock	0	Direct