SEC FORM 4

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

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Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person^*

IORDANOU CONSTANTINE

(Last)

(First)

(Middle)

WESSEX HOUSE, 5TH FLOOR

45 REID STREET

(Street)

HAMILTON

HM 12

(City)

(State)

(Zip)

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

3. Date of Earliest Transaction (Month/Day/Year)
08/29/2011

4. If Amendment, Date of 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

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)
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	Code	V	Amount	(A) or (D)	Price		6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
Common Shares, $.0033 par value per share	08/29/2011		S		70,000⁽⁶⁾	D	$33.9069⁽⁵⁾	422,045⁽⁴⁾	D
Common Shares, $.0033 par value per share								343,245⁽⁴⁾	I	By Limited Liability Company⁽¹⁾
Series B Non-Cumulative Preferred Shares (non-convertible)								67,273.3862	I	By GRAT
Series A Non-Cumulative Preferred Shares (non-convertible)								11,224.4855	I	BY GRAT
Series B Non-Cumulative Preferred Shares (non-convertible)								1,400	I	By spouse
Common Shares, $.0033 par value per share								23,232⁽⁴⁾	I	By children

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 Securities Underlying Derivative Security (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: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
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)	Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	8. Price of Derivative Security (Instr. 5)		10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
Stock Option (right to buy)	$18.757							⁽²⁾	02/23/2016	Common Shares, $.0033 par value per share	132,447⁽³⁾⁽⁴⁾		132,447⁽⁴⁾	D
Stock Option (right to buy)	$18.757							⁽²⁾	02/23/2016	Common Shares, $.0033 par value per share	317,553⁽⁴⁾		317,553⁽⁴⁾	I	By GRAT

Explanation of Responses:

1. 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.

2. The stock option became exercisable in three equal annual installments with the first installment being exercisable on February 23, 2007 and the second and third installments being exercisable on February 23, 2008 and February 23, 2009.

3. On June 9, 2011, 132,447 stock options were distributed from a GRAT. Such options were previously reported as indirectly beneficially held by a GRAT. Following such distribution, the reporting person owns 132,447 stock options directly and 317,553 stock options indirectly by the GRAT.

4. The amount of common shares includes common shares acquired in connection with a 3-for-1 share split effectuated on May 11, 2011.

5. Represents a weighted average sales price; the sales prices range from $33.85 to $33.9501. Upon request, the full sale information regarding the number of shares sold at each price increment will be provided to the Commission or to a security holder of the issuer.

6. The shares were sold in order to satisfy state and federal income tax obligations.

	/s/ Constantine Iordanou	08/30/2011
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* 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).
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