VIKING GLOBAL INVESTORS LP: ATI position timeline

Available 13F reports, 13D and 13G stakes and each Form 3, 4 and 5 line of VIKING GLOBAL INVESTORS LP on ATI, newest first. How the timeline and the estimate are built.

VIKING GLOBAL INVESTORS LP held 1,153,880 ATI shares at 2026-06-30 per its 13F-HR filed 2026-08-14.

the latest 13F is the newest step

period ended2026-06-30
13F 1,153,880 shares
Change vs previous 13F -2,178,963 shares
0.65% of the 13F portfolio, value $227,429,748.
13F-HR 0001103804-26-000006 filed by VIKING GLOBAL INVESTORS LP
Filed 2026-08-14 (acceptance time not in the bulk data set), ingested 2026-10-06 09:57:27 UTC
Acceptance time not in the bulk data set (spec §4.2).
period ended2026-03-31
13F 3,332,843 shares
Change vs previous 13F not available
1.36% of the 13F portfolio, value $484,795,343.
13F-HR 0001103804-26-000004 filed by VIKING GLOBAL INVESTORS LP
Filed 2026-05-15 (acceptance time not in the bulk data set), ingested 2026-10-06 09:58:43 UTC
Acceptance time not in the bulk data set (spec §4.2).