Aon AON

Aon is the 188th largest S&P 500 company by market cap, worth $64.4 billion. 13 directors have filed with the SEC in the last 12 months (who counts), 1 of them an executive. 7 other officers are on file. At 30 Jun 2026, Vanguard was its largest institutional holder, with 10.8% of the company.

CEO: Gregory C. Case
Sector: Financials
Sub-industry: Insurance Brokers
Headquarters: London, United Kingdom
Founded: 1919
More: Wikipedia

Market cap: $64.4B; 188th largest, 23 Oct 2026 close
Revenue: $17.2B; Fiscal year 2025
Price to sales: 3.8; Market cap over revenue
Employees: 60,000; 10-K, 31 Dec 2025
Market cap per employee: $1.1M; Market cap over employees
Connections: 3; S&P 500 companies sharing a director or officer

Largest institutional holders

Each fund group's share of Aon. Where a company has several share classes, the share is of its total value.

13F filings for the quarter to 30 Jun 2026

These five hold 34.2% of Aon.

Board and officers

3 people here also hold roles at other S&P 500 companies.

Roles filed up to 30 Sep 2026

Name	Title
Directors (13)
Gregory C. CasePresident & CEOLast filed 20 Feb 2026	President & CEO
Jose Antonio AlvarezDirector	Director
Jin-Yong CaiDirector	Director
Jeffrey C. CampbellDirectorAlso at Marathon Petroleum	Director
Cheryl A. FrancisDirector	Director
Jo Ann JenkinsDirectorAlso at General Mills	Director
Adriana KaraboutisDirector	Director
Lester B. KnightDirector	Director
Richard C. NotebaertDirector	Director
Gloria SantonaDirector	Director
Sarah G. SmithDirector	Director
Byron SpruellDirector	Director
James G. StavridisDirectorAlso at Fortinet	Director
Officers (7)
Nadin ViraniInterim CFOLast filed 26 Aug 2026	Interim CFO
Anne CoronaChief Commercial OfficerLast filed 17 Mar 2026	Chief Commercial Officer
Lori GoltermannCEO, Regions & North AmericaLast filed 17 Mar 2026	CEO, Regions & North America
Andy MarcellGlobal CEO, Solution LinesLast filed 17 Mar 2026	Global CEO, Solution Lines
Mindy F. SimonChief Operating OfficerLast filed 17 Feb 2026	Chief Operating Officer
Lisa StevensChief Administrative OfficerLast filed 19 Feb 2026	Chief Administrative Officer
Darren ZeidelGeneral CounselLast filed 30 Jul 2026	General Counsel

Companies that share people with Aon

Each person's title here, then at the other company.

Fortinet FTNT
- James G. Stavridis: Director here, Director there
General Mills GIS
- Jo Ann Jenkins: Director here, Director there
Marathon Petroleum MPC
- Jeffrey C. Campbell: Director here, Director there

Aon's market cap since December 2008

Marked weeks are changes in the share count, such as a merger, not market moves.

Weekly, up to 23 Oct 2026

Log scaleShow equal percentage changes as equal steps.

The last week of each year, and the latest week
Week ending	Market cap
23 Oct 2026	$64.4B
26 Dec 2025	$76.7B
27 Dec 2024	$77.9B
29 Dec 2023	$58.3B
30 Dec 2022	$62.1B
31 Dec 2021	$66.2B
25 Dec 2020	$48.1B
27 Dec 2019	$48.6B
28 Dec 2018	$34.6B
29 Dec 2017	$33.5B
30 Dec 2016	$29.3B
25 Dec 2015	$25.2B
26 Dec 2014	$27.4B
27 Dec 2013	$25.1B
28 Dec 2012	$17.7B
30 Dec 2011	$15.1B
31 Dec 2010	$15.3B
25 Dec 2009	$10.7B
26 Dec 2008	$12.6B

Workforce

Headcount at 31 Dec 2025

Employees: 60,000

As of December 31, 2025, we employed approximately 60,000 employees and conducted our operations in more than 120 countries.

Aon Form 10-K

Insider trades

Open-market buys and sales by directors and officers. Grants, option exercises and shares withheld for tax are left out.

Trades from 30 Sep 2025 to 30 Sep 2026

Directors and officers sold $7.8 million of stock in 6 sales and bought $7.8 million in 2 purchases in the 12 months to 30 Sep 2026.

Date	Person	Title	Type	Shares	Value
2 Sep 2026Buy	Lester B. KnightDirector	Director	Buy	20,000	$6.5M
28 Jul 2026Sale	Darren ZeidelGeneral Counsel	General Counsel	Sale	1,900	$718K
17 Jul 2026Sale	Darren ZeidelGeneral Counsel	General Counsel	Sale	1,950	$726K
7 Jul 2026Sale	Darren ZeidelGeneral Counsel	General Counsel	Sale	600	$216K
26 Feb 2026Sale	Darren ZeidelGeneral Counsel	General Counsel	Sale	4,300	$1.4M
17 Feb 2026Sale	Darren ZeidelGeneral Counsel	General Counsel	Sale	5,040	$1.6M
10 Feb 2026Buy	Lester B. KnightDirector	Director	Buy	4,000	$1.3M
5 Nov 2025Sale	Darren ZeidelGeneral Counsel	General Counsel	Sale	8,800	$3.0M

Trades by members of Congress and officials

Trades members of Congress and senior executive branch officials disclosed, including their families'. Amounts are filed as ranges.

Trades from 20 Oct 2023 to 20 Oct 2026

9 people disclosed 22 purchases and 21 sales of Aon stock since October 2023.

Date	Member or official	Type	Amount
25 Sep 2026	Rohit Khanna (House, D-CA)House, D-CA · Sold	Sale	$1,001 to $15,000$1K to $15K
11 May 2026	Donald J Trump (President)President · Sold	Sale	$1,001 to $15,000$1K to $15K
27 Apr 2026	Donald J Trump (President)President · Sold	Sale	$1,001 to $15,000$1K to $15K
27 Mar 2026	Alan Armstrong (Senate, R-OK)Senate, R-OK · Bought	Purchase	$1,001 to $15,000$1K to $15K
24 Feb 2026	Rohit Khanna (House, D-CA)House, D-CA · Sold	Sale	$1,001 to $15,000$1K to $15K
30 Jan 2026	Arjun Mody (Deputy Commissioner)Deputy Commissioner · Sold	Sale	$1,001 to $15,000$1K to $15K
29 Jan 2026	Rohit Khanna (House, D-CA)House, D-CA · Sold	Sale	$1,001 to $15,000$1K to $15K
22 Jan 2026	Rohit Khanna (House, D-CA)House, D-CA · Sold	Sale	$15,001 to $50,000$15K to $50K
22 Jan 2026	Rohit Khanna (House, D-CA)House, D-CA · Sold	Sale	$1,001 to $15,000$1K to $15K
13 Jan 2026	Rohit Khanna (House, D-CA)House, D-CA · Bought	Purchase	$1,001 to $15,000$1K to $15K

Showing 10 of 43 trades

Not on file: no WARN layoff notices under its own name since October 2023.