Walter D. Bay - 31 Mar 2026 Form 4 Insider Report for Arthur J. Gallagher & Co. (AJG)

Reporting relationship: General Counsel
Issuer ticker: AJG
Reported as of: 31 Mar 2026
Net transaction value: $0
SEC form: 4
Accepted by SEC: 01 Apr 2026, 20:02:00 UTC
Prior SEC filing: 17 Mar 2026
Source filing: View source filing
Reporting owner signature: /s/ Monica Norzagaray, by power of attorney

Key filing fact

Walter D. Bay filed Form 4 for Arthur J. Gallagher & Co. (AJG) on 01 Apr 2026.

Key facts

This page summarizes Walter D. Bay's Form 4 filing for Arthur J. Gallagher & Co. (AJG).
3 reported transactions and 9 derivative rows are listed below.
Accepted by SEC: 01 Apr 2026, 20:02.

Change

Previous filing in this sequence was filed on 17 Mar 2026.
Current net transaction value: $0.

Research use

This tells you what this filing adds before you inspect full transaction and derivative tables.
You can trace every row back to the original SEC filing document.

Evidence

Filed on Form 4

Ownership activity is grounded in SEC Form 4 disclosures.

View source filing

Reporting Owners (1)

CIK 0001410235 Primary reporting owner

Bay Walter D.

Relationship: General Counsel
Address: 2850 GOLF ROAD, ROLLING MEADOWS
Signature: /s/ Monica Norzagaray, by power of attorney
Signature date: 01 Apr 2026

Reported non-derivative transactions

Shares, units, or other non-derivative securities reported in this filing.

AJG transaction

Common Stock

Options Exercise

Transaction value
Shares: +1,415
Change %: +1.7%
Price: $215.95^*
Shares after: 83,919
Date: 31 Mar 2026
Ownership: Direct

AJG transaction

Common Stock

Tax liability

Transaction value
Shares: -627
Change %: -0.75%
Price: $215.95^*
Shares after: 83,292
Date: 31 Mar 2026
Ownership: Direct
Footnotes: F1

AJG holding

Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 491
Date: 31 Mar 2026
Ownership: Gallagher 401(k) plan account

Reported derivative securities

Options, warrants, convertible securities, or similar derivative positions disclosed in the filing.

AJG transaction Derivative

Phantom Stock

Options Exercise

Transaction value
Shares: -1,415
Change %: -26%
Price: $0.000000^*
Shares after: 3,995
Date: 31 Mar 2026
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 1,415
Exercise price
Footnotes: F2, F3

AJG holding Derivative

Non-qualified Stock Option

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 24,500
Date: 31 Mar 2026
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 24,500
Exercise price: $127.90
Footnotes: F4

AJG holding Derivative

Non-qualified Stock Option

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 17,630
Date: 31 Mar 2026
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 17,630
Exercise price: $86.17
Footnotes: F4

AJG holding Derivative

Non-qualified Stock Option

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 16,952
Date: 31 Mar 2026
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 16,952
Exercise price: $228.20
Footnotes: F5

AJG holding Derivative

Non-qualified Stock Option

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 11,405
Date: 31 Mar 2026
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 11,405
Exercise price: $158.56
Footnotes: F4

AJG holding Derivative

Non-qualified Stock Option

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 11,350
Date: 31 Mar 2026
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 11,350
Exercise price: $337.74
Footnotes: F4, F6

AJG holding Derivative

Non-qualified Stock Option

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 10,884
Date: 31 Mar 2026
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 10,884
Exercise price: $243.54
Footnotes: F7

AJG holding Derivative

Non-qualified Stock Option

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 9,452
Date: 31 Mar 2026
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 9,452
Exercise price: $177.09
Footnotes: F8

AJG holding Derivative

Notional Stock Units

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 5,829
Date: 31 Mar 2026
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 5,829
Exercise price: $0.000000
Footnotes: F9, F10

^* marks a reported price that did not pass the local price check.

Additional SEC filing notes

Filing notes and footnotes

Explanation of responses 10 footnotes

Footnote F1

The transactions in this report relate solely to the distribution of vested shares under the Age 62 Plan and the withholding of shares to cover applicable income and employment taxes.

Footnote F2

Each share of phantom stock represents a right to receive one share of Gallagher common stock.

Footnote F3

These shares represent awards under the Age 62 Plan, a nonqualified deferred compensation plan of the Company, which have been deemed invested in Company common stock at the election of the reporting person. Participants vest in these awards in the year they attain age 62, or after a one-year period for participants who have attained age 61.

Footnote F4

One-third of this stock option becomes exerciseable on each of the 3rd, 4th, and 5th anniversaries of the grant date.

Footnote F5

One-third of this stock option becomes exercisable on each of the 3rd, 4th, and 5th anniversaries of the grant date.

Footnote F6

Closing price of Gallagher common stock on February 28, 2025.

Footnote F7

One-third of this stock option becomes exercisable on each of the 3rd, 4th, and 5th anniversaries of the grant date.

Footnote F8

One-third of this stock option becomes exercisable on each of the 3rd, 4th, and 5th anniversaries of the grant date.

Footnote F9

Each notional stock unit represents a right to receive one share of Gallagher common stock.

Footnote F10

The notional stock units become payable following the reporting person's separation from service with Gallagher.

SEC remarks

The transactions in this report relate solely to the distribution of vested shares under the Age 62 Plan and the withholding of shares to cover applicable income and employment taxes.