Aon

At a glance

Aon reported 2025 revenue of $17.18B, up 9.4% from $15.7B in 2024. Over 4 years since 2021 ($12.19B), that is growth of about 9% a year. Operating margin was 25.3%, up from 17.1% in 2021. 2025 was the highest revenue year in this period.

In the last 12 months 2 insiders reported 2 open-market purchases ($7.8M) and 6 sales ($7.8M). 4 of the sales were made under pre-arranged 10b5-1 plans. The largest was a purchase of $6.5M by Director Lester B Knight on Sep 3, 2026. Net, insiders were buyers of $76K.

Aon filed 13 current reports (Form 8-K) in the last 12 months, most often for results of operations (5), officer or director change (4), material agreement (2) and other events (2). The latest officer or director change was reported on Aug 17, 2026. It reported a material agreement or a completed acquisition or disposal 2 times.

4 of the 20 investors tracked here held Aon at the last quarter end, worth $548.1M combined. It is the largest weight for Baupost Group (4.2% of its portfolio), followed by Viking Global Investors (1.1%). Added: Viking Global Investors and National Pension Service (Korea). Reduced: Baupost Group and Bridgewater Associates.

Annual results

Fiscal year ends Dec 31 · incorporated in L2

Tracked investors holding (13F)

Weight is the share of each investor's portfolio, as of the quarter end.