Exhibit 15 9.30.14

We are aware that our report dated November 7, 2014 on our review of interim financial information of Arch Capital Group Ltd. and its subsidiaries (the “Company”) for the three-month and nine-month periods ended September 30, 2014 and September 30, 2013 and included in the Company's quarterly report on Form 10-Q for the quarter ended September 30, 2014 is incorporated by reference in the Registration Statement on Form S-3 (Registration No. 333-180329) and in the Registration Statements on Forms S-8 (Registration No. 333- 99974, Registration No. 333-86145, Registration No. 333-82772, Registration No. 333-72182, Registration No. 333-98971, Registration No. 333-124422, Registration No. 333-142835 and Registration No. 333-181308).