ATS Corp /ATS (ATS) Institutional Ownership

Ownership Summary

ATS Corp /ATS (NYSE:ATS) currently has 111 active institutional owners and shareholders as of today (December 2025), that have filed 13F forms with the Securities Exchange Commission (SEC).

• The percentage of Ats owned by institutions changed from 116.3% in September 2025 to 110.4% in December 2025, marking a slight down trend.
• Quarterly data indicates a 4.17% shift in institutional share volume, and the annual owner count reflects a decrease of 13.28%.
• A review of institutional activity for Ats shows 59 of 111 filers increasing their positions, while 38 reduced their stake, and 14 remained unchanged.
• The aggregate institutional position in Ats now stands at 79.48Mn shares as of December 2025, after investors increased their holdings (up by 3.18Mn shares quarter on quarter which is down 5.47Mn shares year over year).
• MASON CAPITAL MANAGEMENT LLC's holding of 15.56Mn shares as of December 31, 2025 makes it the primary institutional investor in Ats, owning 21.61% of the stock.
• Among the most significant buyers of Ats during December 2025 were BANK OF MONTREAL /CAN/ (1.88Mn), NORGES BANK (1.08Mn), FMR LLC (742.18K), EdgePoint Investment Group Inc. (507.49K), ROYAL BANK OF CANADA (442.77K).
• Leading sellers of Ats stock in December 2025 included Turtle Creek Asset Management Inc. (1.33Mn), Beutel, Goodman & Co Ltd. (493.55K), TD Waterhouse Canada Inc. (463.88K), GOLDMAN SACHS GROUP INC (222.51K), BANK OF AMERICA CORP /DE/ (151.31K).
• The top 10 institutional holders of Ats for the quarter ending December 2025 included MASON CAPITAL MANAGEMENT LLC (15.56Mn), ROYAL BANK OF CANADA (7.64Mn), EdgePoint Investment Group Inc. (6.89Mn), Beutel, Goodman & Co Ltd. (5.84Mn), Turtle Creek Asset Management Inc. (5.64Mn), VANGUARD GROUP INC (3.40Mn), BANK OF MONTREAL /CAN/ (3.02Mn), FAIRFAX FINANCIAL HOLDINGS LTD/ CAN (2.49Mn), Connor, Clark & Lunn Investment Management Ltd. (2.49Mn), FMR LLC (2.12Mn).