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)
President & CEO
(Last)
(First)
(Middle)
WESSEX HOUSE, 4TH FLOOR, 45 REID STREET		 3. Date of Earliest Transaction (Month/Day/Year)
12/15/2009
(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, $.01 par value per share 12/15/2009   G V 25 D (3) 162,780 D  
Series B Non-Cumulative Preferred Shares (non-convertible)               62,972 D  
Series A Non-Cumulative Preferred Shares (non-convertible)               10,521 D  
Common Shares, $.01 par value per share               129,415 I By Limited Liability Company (2)
Series B Non-Cumulative Preferred Shares (non-convertible)               1,400 I By spouse
Common Shares, $.01 par value per share               11,850 I By Trusts (1)
Common Shares, $.01 par value per share               11,666 I By children
Series B Non-Cumulative Preferred Shares (non-convertible)               3,000 I By Trusts (1)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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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
Stock Option (right to buy) $ 23.5             01/01/2002(4) 01/01/2012 Common Shares, $.01 par value per share 98,290 (5)   98,290 D  
Stock Option (right to buy) $ 23.5             01/01/2002(4) 01/01/2012 Common Shares, $.01 par value per share 301,710   301,710 I By GRAT

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
IORDANOU CONSTANTINE
WESSEX HOUSE, 4TH FLOOR
45 REID STREET
HAMILTON, D0 HM 12		   X     President & CEO  

Signatures

 /s/ Constantine Iordanou   12/17/2009
**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) These shares are held in irrevocable trusts for the benefit of the reporting person's children. The reporting person disclaims beneficial ownership of these securities and the filing of this report is not an admission that the reporting person is the beneficial owner of these securities for purposes of Section 16 or for any other purpose.
(2) The shared 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.
(3) Represents a bona fide gift to a family member.
(4) 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.
(5) 10,363 of the 98,290 stock options were previously reported as indirectly beneficially owned by a GRAT; on October 7, 2009, the GRAT distributed 10,363 of such stock options to the reporting person and as a result, the reporting person directly owns 98,290 stock options.

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