ACGL: Material agreement · New financial obligation · Other company developments

ITEM 1.01 Entry into a Material Definitive Agreement. On June 9, 2026, Arch Capital Group Ltd. (the “Issuer”), completed the public offering of (i) $600,000,000 aggregate principal amount of 5.250% senior notes due 2036 (the “2036 Notes”) and (ii) $1,400,000,000 aggregate principal amount of 5.950% senior notes due 2056 (the “2056 Notes” and, together with the 2036 Notes, the “Notes”). The Notes have been registered under the Securities Act of 1933, as amended (the “Securities Act”), pursuant to the Issuer’s universal shelf registration statement on Form S-3 (File No. 333-275570), as supplemented by the prospectus supplement dated June 2, 2026, previously filed with the Securities and Exchange Commission under the Securities Act. The Notes were issued pursuant to an indenture (the “Base Indenture”), dated as of May 4, 2004, by and between the Issuer and The Bank of New York Mellon (the “Trustee”), as successor trustee to JPMorgan Chase Bank, as supplemented by a Third Supplemental Indenture, dated as of June 9, 2026, by and between the Issuer and the Trustee (the “Third Supplemental Indenture”, together with the Base Indenture, the “Indenture”). The Notes (v) are senior unsecured obligations of the Issuer and rank equally with any of the other senior unsecured and unsubordinated indebtedness of the Issuer from time to time outstanding, (w) are senior in right of payment to our future indebtedness that is expressly subordinated in right of payment to the Notes, (x) are effectively subordinated to all secured indebtedness of the Issuer to the extent of the value of the assets securing such indebtedness, (y) are effectively subordinated to all existing and future obligations (including amounts owed to holders of reinsurance and insurance policies) of the Issuer’s subsidiar