Kekin Ghelani - 15 Sep 2023 Form 4 Insider Report for Summit Materials, Inc.

Role: Chief Strategy&Growth Officer
Signature: /s/ David Hamm, as Attorney-in-Fact
Issuer symbol: N/A
Transactions as of: 15 Sep 2023
Net transactions value: -$88,960
Form type: 4
Filing time: 18 Sep 2023, 16:32:10 UTC
Previous filing: 24 Feb 2023
Next filing: 01 Mar 2024
SEC: View on sec.gov

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	SUM	Class A Common Stock	Options Exercise		+9,667	+977%		10,656	15 Sep 2023	Direct	F1, F2
transaction	SUM	Class A Common Stock	Tax liability	$88,960	-2,780	-26%	$32.00	7,876	15 Sep 2023	Direct

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	SUM	Restricted Stock Units	Options Exercise	$0	-9,667	-33%	$0.000000	19,334	15 Sep 2023	Class A Common Stock	9,667		Direct	F3, F4

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

Explanation of Responses:

Id	Content
F1	Reflects restricted stock units that upon vesting converted into shares of Class A common stock of the Issuer ("Class A Common Stock") on a one-for-one basis.
F2	Includes 989 shares acquired through the Issuer's Employee Stock Purchase Plan on 5/28/23.
F3	Each restricted stock unit represents a contingent right to receive one share of Class A common stock of the Issuer ("Class A Common Stock"). The restricted stock units will be settled in either Class A Common Stock or cash (or a combination thereof) at the discretion of the Issuer's Human Capital and Compensation Committee.
F4	These restricted stock units vest in three equal annual installments on September 15, 2023, February 28, 2024 and February 28, 2025.