(AMT)

Role: EVP, CFO & Treasurer
Signature: /s/ Marina A. Breed, as attorney-in-fact
Stock symbol: AMT
Transactions as of: Jan 16, 2025
Transactions value $: -$1,433,612
Form type: 4
Date filed: 1/17/2025, 04:11 PM
Previous filing: May 3, 2024
Next filing: Feb 18, 2025
SEC: View on sec.gov

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	AMT	Common Stock	Options Exercise	$1.57M	+16.6K	+26.38%	$94.57	79.4K	Jan 16, 2025	Direct	F1
transaction	AMT	Common Stock	Sale	-$2.59M	-14.3K	-18.01%	$181.03	65.1K	Jan 16, 2025	Direct	F2, F3
transaction	AMT	Common Stock	Sale	-$413K	-2.28K	-3.5%	$181.57	62.8K	Jan 16, 2025	Direct	F2, 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	-16.6K	-50%	$0.00	16.6K	Jan 16, 2025	Common Stock	16.6K	$94.57	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	Includes 119 shares acquired under the issuer's employee stock purchase plan in May 2024.
F2	The sales reported on this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on May 13, 2024.
F3	Represents the weighted average price of shares sold in multiple same-day transactions at prices ranging from $180.41 to $181.40 per share.
F4	Represents the weighted average price of shares sold in multiple same-day transactions at prices ranging from $181.41 to $181.73 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, 2016.