Sec Form 4 Filing - IORDANOU CONSTANTINE @ ARCH CAPITAL GROUP LTD. - 2017-05-08

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

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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 & CEO (Last) (First) (Middle) C/O ARCH CAPITAL GROUP LTD., WATERLOO HOUSE,100 PITTS BAY ROAD 3. Date of Earliest Transaction (MM/DD/YY) 05/08/2017 (Street) PEMBROKE, D0HM 08 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 05/08/2017 A 47,500 A 207,151 D Common Shares, $.0033 par value per share 201,676 I By 2015 GRAT Common Shares, $.0033 par value per share 228,862 I By 2010 GRAT Common Shares, $.0033 par value per share 83,333 I By Limited Liability Company 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 Series C Non-Cumulative Preferred Shares (non-convertible) 6,000 D Series C Non-Cumulative Preferred Shares (non-convertible) 1,800 I By spouse

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 Share Appreciation Right $ 19.293 03/31/2017 G V 6,962 ( 2 ) ( 3 ) 05/06/2019 Common Shares, $.0033 par value per share 6,962 $ 0 14,488 ( 2 ) I By 2010 GRAT Share Appreciation Right $ 19.293 03/31/2017 G V 6,962 ( 2 ) ( 3 ) 05/06/2019 Common Shares, $.0033 par value per share 6,962 $ 0 100,262 ( 2 ) D Stock Option (right to buy) $ 96.26 05/08/2017 A 47,500 ( 4 ) 05/08/2027 Common Shares, $.0033 par value per share 47,500 $ 0 47,500 D

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other IORDANOU CONSTANTINE C/O ARCH CAPITAL GROUP LTD. WATERLOO HOUSE,100 PITTS BAY ROAD PEMBROKE, D0HM 08 X Chairman & CEO Signatures /s/ Constantine Iordanou 05/09/2017 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Represents restricted share units that vest in three equal annual installments on May 8th in each of 2018, 2019 and 2020, subject to the applicable award agreement. ( 2 )On March 31, 2017, 6,962 share appreciation rights were distributed from the 2010 GRAT. Such share appreciation rights were previously reported as indirectly beneficially held by the 2010 GRAT. Following such distribution, the reporting person owns 100,262 share appreciation rights directly and 14,488 indirectly by the 2010 GRAT. ( 3 )The Share Appreciation Right became exercisable in three equal annual installments commencing May 6, 2009, subject to the applicable award agreement. ( 4 )The stock option will become exercisable in three equal annual installments, with the first installment becoming exercisable on May 8, 2018 and the next two installments on May 8, 2019 and May 8, 2020, subject to the applicable award agreement.

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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