William Von Mueffling's Cantillon Capital Management exited Aon PLC (AON) during 2026 Q2, according to the 13F-HR filed with the SEC on July 29, 2026, selling all 1.1M shares. The position had been worth about $353.6M at the prior quarter-end and carried 2.35% of the book. AON had been in the portfolio for 9.5 years, since the quarter ended December 31, 2016.
What did the 2026 Q2 filing report for AON?
As of June 30, 2026, from the 13F-HR filed July 29, 2026.
| Before | After | |
|---|---|---|
| Shares | 1.1M | 0 |
| Reported value | $353.6M | $0 |
| Portfolio weight | 2.35% | 0% |
| Held since | 2016 Q4 | sold out in 2026 Q2 |
| Quarters held | 38 |
What did William Von Mueffling sell?
William Von Mueffling sold 1.1M shares of AON between the quarter ended March 31, 2026 and June 30, 2026. The AON exit was the 19th largest of the quarter's 38 position changes by percent change to portfolio.
Where does AON sit in the William Von Mueffling portfolio?
Before the sale, AON carried 2.35% of the William Von Mueffling portfolio, below the fund's average stock position of 4%. The largest stock position is AVGO at 10.61%. Next come GOOGL at 9.19% and TSM at 8.24%. The three largest stocks together are 28.04% of the book. Across the 2026 Q2 portfolio, William Von Mueffling reported 27 stock positions, with none opened and 11 closed. The total portfolio value is about $665.1M, down 96% from the prior quarter.
How long has William Von Mueffling held AON?
William Von Mueffling held AON for 9.5 years, from the quarter ended December 31, 2016 to March 31, 2026. The weight peaked at 3.32% in 2025 Q1. Last quarter the fund had already cut the position by 12%, so the exit finishes a two-quarter unwind. Every reported trade is on the William Von Mueffling AON trade history page.
Did other funds buy or sell AON in 2026 Q2?
Among the other tracked funds that had filed for 2026 Q2 as of July 29, 2026, 11 still hold AON. The largest buyers of AON this quarter were Ole Andreas Halvorsen, Nathaniel Simons and Eric H. Schoenstein. The largest sellers were Polen Capital Management, Seth Klarman and Eagle Capital Management. Every tracked holder of AON is on the AON ownership page.
FAQ
How many AON shares did William Von Mueffling sell?
William Von Mueffling sold all 1.1M shares of AON it reported a quarter earlier, worth about $353.6M.
When did William Von Mueffling first buy AON?
William Von Mueffling first reported AON in the quarter ended December 31, 2016.
How much of the William Von Mueffling portfolio was AON?
AON was 2.35% of the William Von Mueffling portfolio at the prior quarter-end, and 0% after the sale.
Did other funds sell AON in 2026 Q2?
No other tracked fund sold out of AON in 2026 Q2, but 4 trimmed it; 11 still hold it.