Ownership Submission
FORM 4
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940
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(Print or Type Responses)
1. Name and Address of Reporting Person *
IORDANOU CONSTANTINE
   2. Issuer Name and Ticker or Trading Symbol
ARCH CAPITAL GROUP LTD. [ACGL] 		5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
__X__ Director _____ 10% Owner
__X__ Officer (give title below) _____ Other (specify below)
Chairman, President & CEO
(Last)
(First)
(Middle)
WESSEX HOUSE, 5TH FLOOR, 45 REID STREET		 3. Date of Earliest Transaction (Month/Day/Year)
12/10/2012
(Street)

HAMILTON, D0 HM 12		 4. If Amendment, Date Original Filed(Month/Day/Year)
 6. Individual or Joint/Group Filing(Check Applicable Line)
_X_ Form filed by One Reporting Person
___ Form filed by More than One Reporting Person
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security
(Instr. 3)		 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code
(Instr. 8)		 4. Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)		 5. Amount of Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 3 and 4)		 6. Ownership Form: Direct (D) or Indirect (I)
(Instr. 4)		 7. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V Amount (A) or (D) Price
Common Shares, $.0033 par value per share 12/10/2012   G V 250,000 (1) D $ 0 83,333 (1) I By Limited Liability Company
Common Shares, $.0033 par value per share 12/11/2012   G V 500 D $ 0 385,562 D  
Common Shares, $.0033 par value per share               276,171 (2) I By 2005 GRAT
Common Shares, $.0033 par value per share               488,705 (2) D  
Common Shares, $.0033 par value per share               116,613 I By Limited Liability Company
Common Shares, $.0033 par value per share               11,616 I By child

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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 3)		 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 4. Transaction Code
(Instr. 8)		 5. Number of Derivative Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4, and 5)		 6. Date Exercisable and Expiration Date
(Month/Day/Year)		 7. Title and Amount of Underlying Securities
(Instr. 3 and 4)		 8. Price of Derivative Security
(Instr. 5)		 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 4)		 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 4)		 11. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
IORDANOU CONSTANTINE
WESSEX HOUSE, 5TH FLOOR
45 REID STREET
HAMILTON, D0 HM 12		   X     Chairman, President & CEO  

Signatures

 /s/ Louis T. Petrillo, Attorney in fact   12/18/2012
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1) On December 10, 2012, the reporting person gifted a 1/3 interest in Protaras LLC, a limited liability company, to each of his three children's irrevocable trusts. Prior to gifting the 250,000 common shares, the reporting person owned all of the membership interests in Protaras LLC and served as its sole managing member. The reporting person no longer has a pecuniary interest in 166,667 common shares because the interest is owned by the reporting person's adult daughters who reside outside of his household. The reporting person disclaims benefical ownership of the remaining 83,333 common shares held by his minor daughter's irrevocable trust.
(2) On December 13, 2012, 103,143 common shares were distributed from a GRAT. Following the distribution, the reporting person owns such shares directly and the GRAT owns 276,171 common shares. The 103,143 common shares are included in the reporting person's direct holdings.

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