BLAIR WILLIAM & CO/IL: AON position timeline
Available 13F reports, 13D and 13G stakes and each Form 3, 4 and 5 line of BLAIR WILLIAM & CO/IL on AON, newest first. How the timeline and the estimate are built.
BLAIR WILLIAM & CO/IL held 360,607 AON shares at 2026-06-30 per its 13F-HR filed 2026-08-11.
the latest 13F is the newest step
- period ended2026-06-3013F 360,607 sharesChange vs previous 13F -60,998 shares
0.31% of the 13F portfolio, value $119,609,713.
13F-HR 0001104659-26-093821 filed by BLAIR WILLIAM & CO/IL
Filed (acceptance time not in the bulk data set), ingestedAcceptance time not in the bulk data set (spec §4.2).
- period ended2026-03-3113F 421,605 sharesChange vs previous 13F -74,702 shares
0.39% of the 13F portfolio, value $136,085,646.
13F-HR 0001104659-26-057897 filed by BLAIR WILLIAM & CO/IL
Filed (acceptance time not in the bulk data set), ingestedAcceptance time not in the bulk data set (spec §4.2).
- period ended2025-12-3113F 496,307 sharesChange vs previous 13F -33,466 shares
0.47% of the 13F portfolio, value $175,136,806.
13F-HR 0001104659-26-015563 filed by BLAIR WILLIAM & CO/IL
Filed (acceptance time not in the bulk data set), ingestedAcceptance time not in the bulk data set (spec §4.2).
- period ended2025-09-3013F 529,773 sharesChange vs previous 13F -38,214 shares
0.5% of the 13F portfolio, value $188,906,550.
13F-HR 0001104659-25-109927 filed by BLAIR WILLIAM & CO/IL
Filed (acceptance time not in the bulk data set), ingestedAcceptance time not in the bulk data set (spec §4.2).
- period ended2025-06-3013F 567,987 sharesChange vs previous 13F +13,237 shares
0.56% of the 13F portfolio, value $202,634,886.
13F-HR 0001104659-25-070274 filed by BLAIR WILLIAM & CO/IL
Filed (acceptance time not in the bulk data set), ingestedAcceptance time not in the bulk data set (spec §4.2).
- period ended2025-03-3113F 554,750 sharesChange vs previous 13F -9,497 shares
0.67% of the 13F portfolio, value $221,395,350.
13F-HR 0001104659-25-046545 filed by BLAIR WILLIAM & CO/IL
Filed (acceptance time not in the bulk data set), ingestedAcceptance time not in the bulk data set (spec §4.2).
- period ended2024-12-3113F 564,247 sharesChange vs previous 13F -28,303 shares
0.59% of the 13F portfolio, value $202,654,837.
13F-HR 0001104659-25-011872 filed by BLAIR WILLIAM & CO/IL
Filed (acceptance time not in the bulk data set), ingestedAcceptance time not in the bulk data set (spec §4.2).
- period ended2024-09-3013F 592,550 sharesChange vs previous 13F not available
0.6% of the 13F portfolio, value $205,016,439.
13F-HR 0001104659-24-116499 filed by BLAIR WILLIAM & CO/IL
Filed (acceptance time not in the bulk data set), ingestedAcceptance time not in the bulk data set (spec §4.2).