Sec Form 4 Filing - Hutchings W Preston @ ARCH CAPITAL GROUP LTD. - 2012-02-22

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 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

OMB APPROVAL OMB Number: 3235-0287 Expires: November 30, 2011 Estimated average burden hours per response... 0.5

1. Name and Address of Reporting Person Hutchings W Preston 2. Issuer Name and Ticker or Trading Symbol ARCH CAPITAL GROUP LTD. [ ACGL] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner X __ Officer (give title below) _____ Other (specify below) SVP & Chief Investment Officer (Last) (First) (Middle) WESSEX HOUSE, 5TH FLOOR, 45 REID STREET 3. Date of Earliest Transaction (MM/DD/YY) 02/22/2012 (Street) HAMILTON, D0HM 12 4. If Amendment, Date Original Filed (MM/DD/YY) 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 (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 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 02/22/2012 M 50,000 A $ 15.113 121,769 I By Company ( 2 ) Common Shares, $.0033 par value per share 02/22/2012 F 20,512 ( 4 ) D $ 36.84 101,257 I By Company ( 2 ) Common Shares, $.0033 par value per share 02/23/2012 S 29,488 D $ 36.72 ( 3 ) 71,769 I By Company ( 2 ) Common Shares, $.0033 par value per share 38,148 D

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 (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 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 (MM/DD/YY) 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) $ 15.113 02/22/2012 M 50,000 ( 1 ) 07/01/2015 Common Shares, $.0033 par value per share 50,000 $ 0 100,000 I By Company ( 2 )

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Hutchings W Preston WESSEX HOUSE, 5TH FLOOR 45 REID STREET HAMILTON, D0HM 12 SVP & Chief Investment Officer Signatures /s/ W. Preston Hutchings 02/24/2012 Signature of Reporting Person Date

Explanation of Responses:

( 1 )The stock option became exercisable in three equal annual installments with the first installment being exerciable on July 1, 2005 and the second and third installments being exercisable on July 1, 2006 and July 1, 2007, subject to the applicable award agreemnt. ( 2 )The shares are held by a company which is owned by a family trust; beneficiaries of the family trust are the Reporting Person, his spouse and their minor children. ( 3 )Represents a weighted average sale price; the sales prices range from $37.70 to $37.75. 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. ( 4 )On February 22, 2012, the Reporting Person exercised 50,000 stock options and, under the net settlement provisions of the applicable stock option agreement, 20,512 common shares were withheld in payment of the exercise price.

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).

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.