Argos SEM, LLC → Summit Materials, Inc.

Item 4 of the Schedule 13D is hereby amended and supplemented as follows: On February 10, 2025, pursuant to the Agreement and Plan of Merger, dated as of November 24, 2024, by and among the Issuer, Quikrete Holdings, Inc., a Delaware corporation ("Purchaser"), and Soar Subsidiary, Inc., a Delaware corporation and wholly owned subsidiary of Purchaser ("Merger Sub"), Merger Sub merged with and into the Issuer (the "Merger"), with the Issuer surviving as a wholly owned subsidiary of Purchaser. As a result of the Merger, (i) each issued and outstanding share of Class A Common Stock held by the Reporting Persons was automatically canceled and retired and converted into the right to receive $52.50 per share in cash, without interest and subject to deduction for any required withholding and (ii) the share of preferred stock of the Issuer, par value $0.01 per share, held by Cementos Argos was automatically canceled and retired for no consideration.