ACGL: Material agreement · New financial obligation

ITEM 1.01 Entry into a Material Definitive Agreement. On October 28, 2026, Arch Reinsurance Ltd. (“ArchRe”), a wholly-owned subsidiary of Arch Capital Group Ltd. (“Arch”), entered into Amendment No. 6 to Letter of Credit Facility Agreement (“Amendment No. 6”), as the borrower with Lloyds Bank Corporate Markets plc (“Lloyds”), as Administrative Agent and L/C Agent, which amends the Letter of Credit Facility Agreement, dated as of November 3, 2020, as amended by Amendment No. 1 to Letter of Credit Facility Agreement dated as of October 29, 2021, as further amended by Amendment No. 2 and Joinder to Letter of Credit Facility Agreement dated as of October 27, 2022, as further amended by Amendment No. 3 and Joinder to Letter of Credit Facility Agreement dated as of October 25, 2023, as further amended by Amendment No. 4 to Letter of Credit Facility Agreement dated as of October 30, 2024, and as further amended by Amendment No. 5 to Letter of Credit Facility Agreement dated as of October 29, 2025 (the “Existing L/C Agreement”). The Amendment No. 6 establishes certain changes to the Existing L/C Agreement, including but not limited to, (i) a request for an extension of the Letters of Credit for the 2027 underwriting year of account, (ii) a request for an extension of the last day of the Availability Period (as such term is defined in the Existing L/C Agreement) from May 31, 2026 to May 31, 2027 and (iii) an increase in the maximum Incremental Commitment (as such term is defined in the Existing L/C Agreement) from $50,000,000 to $200,000,000. The Existing L/C Agreement, as amended by Amendment No. 6 (the “Amended L/C Agreement”), provides for a $700 million facility for letters of credit. The foregoing is a summary of certain terms of the Amended L/C Agreement, does not purport