There is a long list of 1756 institutional holders of AMT within the last two holding periods in our database of 13F filers, so we've sorted through to present to you just the top 50 institutional holders of AMT by largest to smallest position reported in the institutional investor's latest 13F filing. In the institutional-holders-of-AMT table below, the initial column indicates the name of each top institutional holder of AMT, with a link to that fund's top holdings. The next columns indicate the amount of AMT stock held by each of the institutional holders of AMT, followed by the AMT position size held by the institution, and finally the date of the quarterly 13F filing period the holdings data represents for that institution.

Holder	Amount	Position Size ($ in 1000's)	As of
Vanguard Group Inc.	61,025,115	$13,174,102	12/31/2023
AMT	61,025,115	$13,174,102	12/31/2023
BlackRock Inc.	36,770,832	$7,938,087	12/31/2023
AMT	36,770,832	$7,938,087	12/31/2023
State Street Corp	20,846,001	$4,535,242	12/31/2023
AMT	20,846,001	$4,535,242	12/31/2023
Cohen & Steers Inc.	16,440,715	$3,549,366	12/31/2023
AMT	16,440,715	$3,549,366	12/31/2023
Wellington Management Group LLP	15,823,622	$3,416,004	12/31/2023
AMT	15,823,622	$3,416,004	12/31/2023
Geode Capital Management LLC	10,430,608	$2,246,872	12/31/2023
AMT	10,430,608	$2,246,872	12/31/2023
Morgan Stanley	7,356,254	$1,588,069	12/31/2023
AMT	7,356,254	$1,588,069	12/31/2023
Deutsche Bank AG	7,246,092	$1,564,286	12/31/2023
AMT	7,246,092	$1,564,286	12/31/2023
Goldman Sachs Group Inc.		$1,564,174	12/31/2023
AMT	7,255,573	$1,566,333	12/31/2023
Put	38,700	$8,355	12/31/2023
Call	28,700	$6,196	12/31/2023
FMR LLC	7,170,373	$1,547,940	12/31/2023
AMT	7,170,373	$1,547,940	12/31/2023
Akre Capital Management LLC	6,804,599	$1,468,977	12/31/2023
AMT	6,804,599	$1,468,977	12/31/2023
Dimensional Fund Advisors LP	6,461,153	$1,394,849	12/31/2023
AMT	6,461,153	$1,394,849	12/31/2023
Principal Financial Group Inc.	6,458,275	$1,394,213	12/31/2023
AMT	6,458,275	$1,394,213	12/31/2023
Price T Rowe Associates Inc. MD	6,221,901	$1,343,186	12/31/2023
AMT	6,221,901	$1,343,186	12/31/2023
Invesco Ltd.	5,669,780	$1,223,992	12/31/2023
AMT	5,669,780	$1,223,992	12/31/2023
Legal & General Group Plc	5,451,859	$1,176,951	12/31/2023
AMT	5,451,859	$1,176,951	12/31/2023
Northern Trust Corp	5,359,239	$1,156,953	12/31/2023
AMT	5,359,239	$1,156,953	12/31/2023
Nuveen Asset Management LLC	5,318,809	$1,152,584	12/31/2023
AMT	5,318,809	$1,152,584	12/31/2023
Jennison Associates LLC	5,299,306	$1,144,014	12/31/2023
AMT	5,299,306	$1,144,014	12/31/2023
Edgewood Management LLC	4,985,879	$1,076,352	12/31/2023
AMT	4,985,879	$1,076,352	12/31/2023
Norges Bank	4,872,607	$1,051,898	12/31/2023
AMT	4,872,607	$1,051,898	12/31/2023
Charles Schwab Investment Management Inc.	4,808,113	$1,037,975	12/31/2023
AMT	4,808,113	$1,037,975	12/31/2023
Capital Research Global Investors	4,437,051	$957,872	12/31/2023
AMT	4,437,051	$957,872	12/31/2023
Bank of America Corp DE		$942,825	12/31/2023
AMT	4,383,455	$946,300	12/31/2023
Put	64,200	$13,859	12/31/2023
Call	48,100	$10,384	12/31/2023
Wells Fargo & Company MN	4,290,966	$926,334	12/31/2023
AMT	4,290,966	$926,334	12/31/2023
Alliancebernstein L.P.	3,911,207	$844,351	12/31/2023
AMT	3,911,207	$844,351	12/31/2023
Brown Advisory Inc.	3,707,574	$800,391	12/31/2023
AMT	3,707,574	$800,391	12/31/2023
Ameriprise Financial Inc.	3,668,106	$792,014	12/31/2023
AMT	3,668,106	$792,014	12/31/2023
Clearbridge Investments LLC	3,384,864	$730,724	12/31/2023
AMT	3,384,864	$730,724	12/31/2023
Bank of New York Mellon Corp	3,287,512	$709,708	12/31/2023
AMT	3,287,512	$709,708	12/31/2023
Amundi	2,886,246	$612,784	12/31/2023
AMT	2,886,246	$612,784	12/31/2023
1832 Asset Management L.P.	2,766,446	$597,220	12/31/2023
AMT	2,766,446	$597,220	12/31/2023
Putnam Investments LLC	2,666,350	$575,612	12/31/2023
AMT	2,666,350	$575,612	12/31/2023
JPMorgan Chase & Co.		$567,386	12/31/2023
AMT	2,394,946	$517,021	12/31/2023
Call	281,500	$60,770	12/31/2023
Put	48,200	$10,405	12/31/2023
Massachusetts Financial Services Co. MA	2,578,811	$556,714	12/31/2023
AMT	2,578,811	$556,714	12/31/2023
UBS Group AG		$531,045	12/31/2023
AMT	2,513,107	$542,530	12/31/2023
Put	144,600	$31,216	12/31/2023
Call	91,400	$19,731	12/31/2023
UBS Asset Management Americas Inc.	2,453,738	$529,713	12/31/2023
AMT	2,453,738	$529,713	12/31/2023
Royal Bank of Canada	2,315,007	$499,762	12/31/2023
AMT	2,315,007	$499,762	12/31/2023
Cantillon Capital Management LLC	2,138,424	$461,643	12/31/2023
AMT	2,138,424	$461,643	12/31/2023
Janus Henderson Group PLC	2,114,032	$456,395	12/31/2023
AMT	2,114,032	$456,395	12/31/2023
Public Investment Fund	1,892,998	$408,660	12/31/2023
AMT	1,892,998	$408,660	12/31/2023
Twin Tree Management LP		$391,455	12/31/2023
Call	1,813,300	$391,455	12/31/2023
Voya Investment Management LLC	1,715,235	$370,285	12/31/2023
AMT	1,715,235	$370,285	12/31/2023
CIBC Private Wealth Group LLC	1,649,785	$356,155	12/31/2023
AMT	1,649,785	$356,155	12/31/2023
Neuberger Berman Group LLC	1,639,794	$353,958	12/31/2023
AMT	1,639,794	$353,958	12/31/2023
Mitsubishi UFJ Trust & Banking Corp	1,624,451	$351,014	12/31/2023
AMT	1,624,451	$351,014	12/31/2023
California Public Employees Retirement System	1,592,843	$343,863	12/31/2023
AMT	1,592,843	$343,863	12/31/2023
Fisher Asset Management LLC	1,589,861	$343,219	12/31/2023
AMT	1,589,861	$343,219	12/31/2023
Loring Wolcott & Coolidge Fiduciary Advisors LLP MA	1,473,280	$318,052	12/31/2023
AMT	1,473,280	$318,052	12/31/2023
Rare Infrastructure Ltd	1,459,639	$315,107	12/31/2023
AMT	1,459,639	$315,107	12/31/2023