ARCH CAPITAL GROUP LTD. — Director's Dealing 2010

Dec 21, 2010

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: ARCH CAPITAL GROUP LTD. (ACGL)
CIK: 0000947484
Period of Report: 2010-12-14

Reporting Person: IORDANOU CONSTANTINE (Director, Chairman, President & CEO)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2010-12-14	Common Shares, $.01 par value per share	G	25	—	Disposed	152735	Direct

Holdings (Non-Derivative)

Security	Shares	Ownership
Series B Non-Cumulative Preferred Shares (non-convertible)	67273.3862	Indirect
Series A Non-Cumulative Preferred Shares (non-convertible)	11224.4855	Indirect
Common Shares, $.01 par value per share	129415	Indirect
Series B Non-Cumulative Preferred Shares (non-convertible)	1400	Indirect
Common Shares, $.01 par value per share	7744	Indirect

Holdings (Derivative)

Security	Exercise Price	Expiration	Underlying	Shares	Ownership
Stock Option (right to buy)	$23.50	2012-01-01	Common Shares, $.01 par value per share (184119)	184119	Direct
Stock Option (right to buy)	$23.50	2012-01-01	Common Shares, $.01 par value per share (215881)	215881	Indirect

Footnotes

F1: Represents a bona fide gift to a family member.

F2: The shares are owned by Mathiatis LLC, a limited liability company. The reporting person owns all of the membership interests in Mathiatis LLC and serves as its sole managing member.

F3: The stock option became exercisable in three equal annual installments with the first installment being exercisable on January 1, 2002 and the second and third installments being exercisable on January 1, 2003 and January 1, 2004.

F4: On December 29, 2009, 15,554 stock options were distributed from a GRAT. On December 14, 2010, 70,275 stock options were distributed from a GRAT. Such stock options were previously reported as indirectly beneficially held by a GRAT. Following such distributions, the reporting person directly owns 184,119 stock options.