Institutional HoldersBeta

Who holds a company, from every 13F filed for the quarter, one row per filer exactly as filed, against the latest share count the company reported.

ATS Corp /ATS

CIK 0001394832ATS· quarter ending 2026-06-30

Shares outstanding

98,106,632

as of 2026-03-31 · 40-F cover page, filed 2026-05-28

Held by 13F filers

81,596,752

83.2% of shares outstanding

Holders

141

+10 vs 2026-03-31 · 25 new, 15 exited

Value

$2.4B

shares -4.4% vs prior quarter

Share classes (cover page of the 40-F filed 2026-05-28, as of 2026-03-31)

Class	Listed	Shares outstanding	Held by 13F filers	% of class	Holders	CUSIP
Common stock	ATS · NYSE	98,106,632	81,596,752	83.2%	141	00217Y104

Each class is compared with its own share count; classes are not added together. A class that is not exchange-listed cannot be held by 13F filers.

Securities (CUSIPs held in 13F this quarter)

tick to combine

Count	CUSIP	Class (as filers write it)	Holders	Shares held	Class shares	% of class	Value	Options	Mapped via
	00217Y104	COM	141	81,596,752	98,106,632	83.2%	$2.4B	1 call / 2 put	13DG	holders →
	00217Y955	EQUITYnot common	1	31,937	—	—	$920K	—	prefix	holders →

Totals combine the ticked CUSIPs and update as you tick: common-stock classes by default; preferreds, notes, warrants and depositary shares are listed but not counted. "holders →" shows a single CUSIP on its own. Bonds are held as a principal amount, not shares. Options positions are never counted as holdings.

Top holders (141 of 141 · 00217Y104)

change vs 2026-03-31

#	Filer	Shares	% of class	Value	Change
1	MASON CAPITAL MANAGEMENT LLC	16,404,170	16.72%	$472.1M	—
2	ROYAL BANK OF CANADA	7,881,423	8.03%	$226.8M	+119,585 (+1.5%)
3	EdgePoint Investment Group Inc.	7,004,577	7.14%	$201.7M	-163,535 (-2.3%)
4	Beutel, Goodman & Co Ltd.	4,796,922	4.89%	$138.2M	-657,827 (-12.1%)
5	TURTLE CREEK ASSET MANAGEMENT INC.	3,084,567	3.14%	$88.8M	-1,812,102 (-37.0%)
6	BANK OF MONTREAL /CAN/	3,062,973	3.12%	$88.2M	-52,387 (-1.7%)
7	FMR LLC	2,905,456	2.96%	$83.7M	+627,984 (+27.6%)
8	FAIRFAX FINANCIAL HOLDINGS LTD/ CAN	2,486,400	2.53%	$70.5M	—
9	VANGUARD CAPITAL MANAGEMENT LLC	2,398,431	2.44%	$69.1M	+31,701 (+1.3%)
10	Jupiter Topco LLC	2,322,073	2.37%	$66.9M	NEW
11	TD Waterhouse Canada Inc.	1,683,683	1.72%	$47.4M	+49,234 (+3.0%)
12	Hill City Capital, LP	1,649,857	1.68%	$47.5M	—
13	ACK Asset Management LLC	1,500,000	1.53%	$43.2M	-346,196 (-18.8%)
14	FIL Ltd	1,326,851	1.35%	$38.2M	-451,330 (-25.4%)
15	Alberta Investment Management Corp	1,177,491	1.20%	$33.9M	+237,300 (+25.2%)
16	Scheer, Rowlett & Associates Investment Management Ltd.	1,175,268	1.20%	$33.8M	-6,669 (-0.6%)
17	BANK OF AMERICA CORP /DE/	1,122,152	1.14%	$32.3M	+176,277 (+18.6%)
18	Connor, Clark & Lunn Investment Management Ltd.	1,089,460	1.11%	$31.4M	-1,175,297 (-51.9%)
19	NORGES BANK	1,084,181	1.11%	$31.2M	NEW
20	Clearbridge Investments, LLC	1,060,487	1.08%	$30.5M	-30,804 (-2.8%)
21	Legal & General Group Plc	1,056,408	1.08%	$30.4M	+444,719 (+72.7%)
22	TD Asset Management Inc	1,003,596	1.02%	$28.9M	-418,863 (-29.4%)
23	Marathon Asset Management Ltd	954,485	0.97%	$27.5M	-139,426 (-12.7%)
24	NATIONAL BANK OF CANADA /FI/	855,316	0.87%	$24.2M	+207,034 (+31.9%)
25	VAN LANSCHOT KEMPEN INVESTMENT MANAGEMENT N.V.	795,619	0.81%	$32.5M	-67,867 (-7.9%)
26	MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd.	788,784	0.80%	$22.7M	+30,471 (+4.0%)
27	VANGUARD FIDUCIARY TRUST CO	724,271	0.74%	$20.9M	-3,787 (-0.5%)
28	Langdon Equity Partners	600,000	0.61%	$17.3M	NEW
29	MASSACHUSETTS FINANCIAL SERVICES CO /MA/	540,733	0.55%	$22.1M	+6,776 (+1.3%)
30	MACKENZIE FINANCIAL CORP	524,774	0.53%	$21.5M	-91,730 (-14.9%)
31	TORONTO DOMINION BANK	406,916	0.41%	$11.7M	+313,741 (+336.7%)
32	Public Sector Pension Investment Board	378,001	0.39%	$10.9M	+21,164 (+5.9%)
33	1832 Asset Management L.P.	355,745	0.36%	$10.2M	-45,951 (-11.4%)
34	Waratah Capital Advisors Ltd.	334,923	0.34%	$9.6M	+110,940 (+49.5%)
35	CIBC WORLD MARKET INC.	327,087	0.33%	$9.4M	-19,519 (-5.6%)
36	ArrowMark Colorado Holdings LLC	280,000	0.29%	$8.1M	+106,000 (+60.9%)
37	Vanguard Global Advisers, LLC	274,103	0.28%	$7.9M	+15,105 (+5.8%)
38	Roubaix Capital, LLC	246,909	0.25%	$7.1M	NEW
39	CHARLES SCHWAB INVESTMENT MANAGEMENT INC	243,525	0.25%	$7.0M	+4,871 (+2.0%)
40	MORGAN STANLEY	234,236	0.24%	$6.7M	+133,846 (+133.3%)
41	GOLDMAN SACHS GROUP INC	223,762	0.23%	$6.4M	+171,511 (+328.2%)
42	UBS Group AG	222,553	0.23%	$6.4M	-5,075 (-2.2%)
43	SCOTIA CAPITAL INC.	212,719	0.22%	$6.0M	+20,189 (+10.5%)
44	Dixon Mitchell Investment Counsel Inc.	211,025	0.22%	$6.1M	—
45	JANE STREET GROUP, LLC	199,635	0.20%	$5.7M	+116,994 (+141.6%)
46	Granite Investment Partners, LLC	195,894	0.20%	$5.6M	+22,863 (+13.2%)
47	Van Berkom & Associates Inc.	188,066	0.19%	$5.4M	-326,654 (-63.5%)
48	Focus Partners Wealth	181,975	0.19%	$5.2M	—
49	FIRST TRUST ADVISORS LP	181,592	0.19%	$5.2M	+27,189 (+17.6%)
50	Swiss National Bank	168,000	0.17%	$4.8M	+3,600 (+2.2%)
51	DIMENSIONAL FUND ADVISORS LP	167,149	0.17%	$4.8M	+44,693 (+36.5%)
52	Candelo Capital Management LP	165,100	0.17%	$4.8M	+13,412 (+8.8%)
53	Delaney Capital Management Ltd.	160,392	0.16%	$4.6M	+6,315 (+4.1%)
54	NewGen Asset Management Ltd	150,000	0.15%	$4.3M	NEW
55	CIBC Asset Management Inc	138,246	0.14%	$4.0M	+4,060 (+3.0%)
56	Front Street Capital Management, Inc.	124,973	0.13%	$3.6M	-136,115 (-52.1%)
57	HARBOR CAPITAL ADVISORS, INC.	115,198	0.12%	$3.3M	+12,030 (+11.7%)
58	LOUISBOURG INVESTMENTS INC.	111,104	0.11%	$3.2M	+26,249 (+30.9%)
59	Polar Asset Management Partners Inc.	105,203	0.11%	$3.0M	NEW
60	BRITISH COLUMBIA INVESTMENT MANAGEMENT Corp	101,546	0.10%	$2.9M	+31,124 (+44.2%)
61	K.J. Harrison & Partners Inc	100,000	0.10%	$2.9M	NEW
62	MONTRUSCO BOLTON INVESTMENTS INC.	99,056	0.10%	$2.9M	-71,900 (-42.1%)
63	SEI INVESTMENTS CO	97,376	0.10%	$2.8M	-70,444 (-42.0%)
64	PCJ Investment Counsel Ltd.	85,640	0.09%	$2.5M	+35,640 (+71.3%)
65	LAZARD ASSET MANAGEMENT LLC	83,052	0.08%	$2.4M	+13,140 (+18.8%)
66	Canoe Financial LP	83,024	0.08%	$2.4M	-4,406 (-5.0%)
67	HALLSTATT ADVISORS L.P.	83,020	0.08%	$2.4M	NEW
68	CITADEL ADVISORS LLC	82,308	0.08%	$2.4M	+1,069 (+1.3%)
69	MANUFACTURERS LIFE INSURANCE COMPANY, THE	73,654	0.08%	$2.1M	-476 (-0.6%)
70	GEODE CAPITAL MANAGEMENT, LLC	69,598	0.07%	$2.0M	+800 (+1.2%)
71	VANGUARD ASSET MANAGEMENT, Ltd	66,830	0.07%	$1.9M	—
72	CenterBook Partners LP	65,180	0.07%	$1.9M	NEW
73	Nuveen, LLC	62,584	0.06%	$1.8M	—
74	Caldwell Investment Management Ltd.	60,800	0.06%	$1.7M	—
75	BOOTHBAY FUND MANAGEMENT, LLC	59,867	0.06%	$1.7M	NEW
76	Federation des caisses Desjardins du Quebec	54,947	0.06%	$1.6M	-58,100 (-51.4%)
77	Zurcher Kantonalbank (Zurich Cantonalbank)	54,361	0.06%	$1.6M	+22,911 (+72.8%)
78	VAN ECK ASSOCIATES CORP	46,507	0.05%	$1.3M	+22,236 (+91.6%)
79	GUARDIAN CAPITAL LP	46,433	0.05%	$1.3M	-522 (-1.1%)
80	INTACT INVESTMENT MANAGEMENT INC.	40,489	0.04%	$1.2M	-12,900 (-24.2%)
81	Aviso Financial Inc.	40,111	0.04%	$1.2M	-5,649 (-12.3%)
82	PenderFund Capital Management Ltd.	37,700	0.04%	$1.1M	+17,700 (+88.5%)
83	CITIGROUP INC	36,651	0.04%	$1.1M	+9,835 (+36.7%)
84	BANK OF NOVA SCOTIA TRUST CO	35,291	0.04%	$1.0M	+959 (+2.8%)
85	XTX Topco Ltd	35,013	0.04%	$1.0M	NEW
86	SUSQUEHANNA INTERNATIONAL GROUP, LLP	34,791	0.04%	$1.0M	NEW
87	AMERICAN CENTURY COMPANIES INC	32,500	0.03%	$937K	NEW
88	Engineers Gate Manager LP	31,363	0.03%	$903K	+18,311 (+140.3%)
89	Verition Fund Management LLC	29,513	0.03%	$849K	NEW
90	PUBLIC EMPLOYEES RETIREMENT SYSTEM OF OHIO	28,366	0.03%	$817K	+1,031 (+3.8%)
91	FRANKLIN RESOURCES INC	25,412	0.03%	$732K	-222,055 (-89.7%)
92	Squarepoint Ops LLC	24,760	0.03%	$713K	NEW
93	SIG North Trading, ULC	22,575	0.02%	$650K	-3,700 (-14.1%)
94	ExodusPoint Capital Management, LP	22,100	0.02%	$636K	+50 (+0.2%)
95	Vanguard Investments Australia, Ltd.	21,874	0.02%	$630K	+2,559 (+13.2%)
96	WELLS FARGO & COMPANY/MN	19,748	0.02%	$568K	+18,241 (+1210.4%)
97	BARCLAYS PLC	16,814	0.02%	$484K	+13,836 (+464.6%)
98	ALLIANCEBERNSTEIN L.P.	16,380	0.02%	$462K	+7,420 (+82.8%)
99	Pictet Asset Management Holding SA	15,987	0.02%	$461K	-436 (-2.7%)
100	Purpose Unlimited Inc.	15,754	0.02%	$454K	-12,813 (-44.9%)
101	Northwest & Ethical Investments L.P.	15,573	0.02%	$448K	+4,590 (+41.8%)
102	Aberdeen Group plc	13,483	0.01%	$388K	-12,754 (-48.6%)
103	TRUE Private Wealth Advisors	12,080	0.01%	$348K	—
104	Savant Capital, LLC	11,997	0.01%	$345K	-660 (-5.2%)
105	Mariner, LLC	11,879	0.01%	$342K	-4,358 (-26.8%)
106	Investment Management Corp of Ontario	11,816	0.01%	$340K	+100 (+0.9%)
107	HRT FINANCIAL LP	10,824	0.01%	$311K	NEW
108	DEUTSCHE BANK AG\	10,811	0.01%	$311K	+59 (+0.5%)
109	STIFEL FINANCIAL CORP	9,016	0.01%	$259K	-2,875 (-24.2%)
110	Campbell & CO Investment Adviser LLC	8,503	0.01%	$245K	+76 (+0.9%)
111	Gotham Asset Management, LLC	8,395	0.01%	$242K	+724 (+9.4%)
112	Invesco Ltd.	8,279	0.01%	$238K	-334,897 (-97.6%)
113	Quadrature Capital Ltd	8,100	0.01%	$233K	NEW
114	SkyView Investment Advisors, LLC	7,500	0.01%	$216K	-3,466 (-31.6%)
115	Fieldview Capital Management, LLC	7,408	0.01%	$214K	NEW
116	Tower Research Capital LLC (TRC)	3,900	0.00%	$112K	-4,000 (-50.6%)
117	ACADIAN ASSET MANAGEMENT LLC	2,900	0.00%	$83K	-2,500 (-46.3%)
118	Russell Investments Group, Ltd.	1,758	0.00%	$51K	-1,070 (-37.8%)
119	JPMORGAN CHASE & CO	1,382	0.00%	$38K	+419 (+43.5%)
120	State of Wyoming	1,162	0.00%	$33K	-53 (-4.4%)
121	Smartleaf Asset Management LLC	1,052	0.00%	$29K	—
122	Hillsdale Investment Management Inc.	900	0.00%	$26K	+300 (+50.0%)
123	SIMPLEX TRADING, LLC	846	0.00%	$24K	NEW
124	Guardian Partners Inc.	760	0.00%	$22K	NEW
125	Blue Trust, Inc.	733	0.00%	$21K	—
126	Pacer Advisors, Inc.	604	0.00%	$17K	+365 (+152.7%)
127	Clearstead Advisors, LLC	539	0.00%	$16K	NEW
128	Farther Finance Advisors, LLC	263	0.00%	$8K	—
129	OSAIC HOLDINGS, INC.	208	0.00%	$6K	-146 (-41.2%)
130	HANTZ FINANCIAL SERVICES, INC.	168	0.00%	$5K	-2,549 (-93.8%)
131	NBH Bank	113	0.00%	$3K	NEW
132	WealthCollab, LLC	89	0.00%	$3K	—
133	FIDUCIARY FINANCIAL ADVISORS	80	0.00%	$2K	NEW
134	BlackRock, Inc.	58	0.00%	$2K	—
135	Rockefeller Capital Management L.P.	48	0.00%	$1K	NEW
136	Silver Grove Financial Group, Inc.	36	0.00%	$1K	NEW
137	Bell Investment Advisors, Inc	35	0.00%	$1K	+15 (+75.0%)
138	EverSource Wealth Advisors, LLC	20	0.00%	$576	-36 (-64.3%)
139	Larson Financial Group LLC	12	0.00%	$345	-186 (-93.9%)
140	Caitong International Asset Management Co., Ltd	4	0.00%	$115	-13 (-76.5%)
141	Leonteq Securities AG	4	0.00%	$164	—

Exited since 2026-03-31 (15 filers; largest 15 shown)

JANUS HENDERSON GROUP PLC	−2,297,214
Vinva Investment Management Ltd	−2,088,947
PRINCIPAL FINANCIAL GROUP INC	−620,840
ROYCE & ASSOCIATES LP	−179,500
D. E. Shaw & Co., Inc.	−30,200
Numerai GP LLC	−27,538
Balyasny Asset Management L.P.	−14,124
MARSHALL WACE, LLP	−9,920
Brevan Howard Capital Management LP	−8,424
Orion Porfolio Solutions, LLC	−7,994
NewEdge Advisors, LLC	−214
WELLINGTON-ALTUS USA INC.	−125
Bank of Jackson Hole Trust	−113
Root Financial Partners, LLC	−40
JONES FINANCIAL COMPANIES LLLP	−36

Large holders from 13D/13G (latest per reporting person, last 2 years)

Filed when a holder crosses 5% or changes materially, so often more current than the quarter-end 13F. Percentages are the filer's own, against the share count they used.

Reporting person	Form	Filed	Event	Shares	% of class
Turtle Creek Asset Management Inc.	SCHEDULE 13G/A	2026-05-15	2026-03-31	4,896,669	4.99%
Royal Bank of Canada	SCHEDULE 13G/A	2026-02-13	2025-12-31	6,486,790	6.62%
EdgePoint Investment Group Inc.	SCHEDULE 13G/A	2025-08-14	2025-06-30	6,434,005	6.59%
BANK OF NOVA SCOTIA	SCHEDULE 13G	2025-07-21	2025-06-30	1,443,772	1.479%

Source: SEC Form 13F-HR information tables for the quarter ending 2026-06-30 (filed within 45 days of quarter end; amendments applied; values normalised to dollars), the share count from the company's latest 10-K/10-Q XBRL cover page, and Schedule 13D/13G filings. Each row is a legal 13F filer as filed — related entities (e.g. Vanguard's advisers) are not merged. Retail brokerage accounts are not reported on 13F, so the remainder is mostly retail and insiders.