(AMT)

Role: President and CEO, Director
Signature: /s/ Marina A. Breed, as attorney-in-fact
Stock symbol: AMT
Transactions as of: Mar 4, 2024
Transactions value $: -$389,329
Form type: 4
Date filed: 3/6/2024, 05:00 PM
Previous filing: Mar 1, 2024
Next filing: Mar 12, 2024

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	AMT	Common Stock	Options Exercise	$265K	+3.27K	+5.59%	$81.18	61.6K	Mar 4, 2024	Direct
transaction	AMT	Common Stock	Sale	-$338K	-1.7K	-2.75%	$199.48	59.9K	Mar 4, 2024	Direct	F1, F2
transaction	AMT	Common Stock	Sale	-$185K	-919	-1.53%	$201.19	59K	Mar 4, 2024	Direct	F1, F3
transaction	AMT	Common Stock	Sale	-$131K	-650	-1.1%	$201.80	58.4K	Mar 4, 2024	Direct	F1, F4

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
transaction	AMT	Option to Purchase Common Stock	Options Exercise	$0	-3.27K	-100%	$0.00^*	0	Mar 4, 2024	Common Stock	3.27K	$81.18	Direct	F5

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Buy Plan / Sale Plan: These are also open market purchases/sales of shares, but in this case the transaction is part of a trading plan. Rule 10b5-1 allows insiders to setup a trading plan to buy/sell stocks over a certain period of time. Since the purchases/sales are predetermined, this protects the insiders from violating insider trading law.

Transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c).

Explanation of Responses:

Id	Content
F1	The sales reported on this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on April 27, 2023.
F2	Represents the weighted average price of shares sold in multiple same-day transactions at prices ranging from $199.03 to $199.94 per share.
F3	Represents the weighted average price of shares sold in multiple same-day transactions at prices ranging from $200.44 to $201.43 per share.
F4	Represents the weighted average price of shares sold in multiple same-day transactions at prices ranging from $201.58 to $202.23 per share.
F5	This option was granted pursuant to the 2007 Equity Incentive Plan, as amended, and is exercisable in 25% cumulative annual increments beginning March 10, 2015.