MEAD CHRISTOPHER E (VICE PRESIDENT) sold 13.6% of their position (3.50K shares) of ARTHUR J. GALLAGHER & CO. on the open market

Open‑market sale worth $899.6K — a moderate reduction. Review remaining holdings and any 10b5‑1 plan disclosures.

S · 1 sale

MEAD CHRISTOPHER E

Filed: 8/20/2026ACC: 0000354190-26-000195

InsiderMEAD CHRISTOPHER ECIK 1737644

→

IssuerARTHUR J. GALLAGHER & CO.CIK 354190

Officer· VICE PRESIDENT

Since Mar 2026

-3.50K

Net shares

Net seller

$899.6K

Total sold

Open market trades

0B · 1S

Total transactions

3.50K acquired · 7K disposed

Non-Derivative Transactions2

Common Stock

Direct

M · Option Exercise

+3.50K

Price / share

$86.17

Trade value

$301.60K

% of position

15.7%

8/19/2026

22.22K→25.72K

Common Stock

Direct

S · Sale

−3.50K

Price / share

$257.02

Trade value

$899.59K

% of position

13.6%

8/19/2026

25.72K→22.22K

Total

Net shares

+0.00

Net value

-$597.99K

Security	Date	Type	Shares	Price / Share	Trade Value	% of Position	Held Before	Held After
Common Stock Direct	8/19/2026	M · Option Exercise	+3.50K	$86.17	$301.60K	15.7%	22.22K	25.72K
Common Stock Direct	8/19/2026	S · Sale	−3.50K	$257.02	$899.59K	13.6%	25.72K	22.22K
Total			+0.00		-$597.99K

Derivative Transactions1

Non-qualified Stock Option

Direct

M · Option Exercise

Converts to

Common Stock

3.50K shares

−3.50K

Strike price

86.17

Held after

7.59K

Exercisable

—

8/19/2026

Security	Converts To	Date	Type	Shares	Strike Price	Exercisable	Held After
Non-qualified Stock Option Direct	Common Stock3.50K shares	8/19/2026	M · Option Exercise	−3.50K	86.17	—	7.59K

Non-Derivative Holdings (Post-Transaction)1

Common Stock

Indirect

Shares owned491.10

Total

491.10 indirect491.10

Security Title	Shares Owned	Ownership Type
Common Stock	491.10	Indirect
Total	491.10	491.10 indirect

Derivative Holdings (Post-Transaction)8

Phantom Stock

Direct

Underlying security

Common Stock

Underlying shares

21.94K

Shares owned

21.94K

Exercise price

Expiration

—

Exercise window

—

Non-qualified Stock Option

Direct

Underlying security

Common Stock

Underlying shares

8.42K

Shares owned

8.42K

Exercise price

158.56

Expiration

—

Exercise window

—

Non-qualified Stock Option

Direct

Underlying security

Common Stock

Underlying shares

8.26K

Shares owned

8.26K

Exercise price

337.74

Expiration

—

Exercise window

—

Notional Stock Units

Direct

Underlying security

Common Stock

Underlying shares

1.98K

Shares owned

1.98K

Exercise price

Expiration

—

Exercise window

—

Non-qualified Stock Option

Direct

Underlying security

Common Stock

Underlying shares

11.72K

Shares owned

11.72K

Exercise price

127.90

Expiration

—

Exercise window

—

Non-qualified Stock Option

Direct

Underlying security

Common Stock

Underlying shares

7.37K

Shares owned

7.37K

Exercise price

243.54

Expiration

—

Exercise window

—

Non-qualified Stock Option

Direct

Underlying security

Common Stock

Underlying shares

7.01K

Shares owned

7.01K

Exercise price

177.09

Expiration

—

Exercise window

—

Non-qualified Stock Option

Direct

Underlying security

Common Stock

Underlying shares

12.34K

Shares owned

12.34K

Exercise price

228.20

Expiration

—

Exercise window

—

Total

Underlying

79.06K

Owned

79.06K

Security	Underlying	Exercise Price	Exercise Window	Expiration	Underlying Shares	Shares Owned
Phantom Stock Direct	Common Stock		—	—	21.94K	21.94K
Non-qualified Stock Option Direct	Common Stock	158.56	—	—	8.42K	8.42K
Non-qualified Stock Option Direct	Common Stock	337.74	—	—	8.26K	8.26K
Notional Stock Units Direct	Common Stock		—	—	1.98K	1.98K
Non-qualified Stock Option Direct	Common Stock	127.90	—	—	11.72K	11.72K
Non-qualified Stock Option Direct	Common Stock	243.54	—	—	7.37K	7.37K
Non-qualified Stock Option Direct	Common Stock	177.09	—	—	7.01K	7.01K
Non-qualified Stock Option Direct	Common Stock	228.20	—	—	12.34K	12.34K
Total					79.06K	79.06K