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
(Last)
(First)
(Middle)
C/O ARCH CAPITAL GROUP LTD., WATERLOO HOUSE,100 PITTS BAY ROAD		 3. Date of Earliest Transaction (Month/Day/Year)
05/09/2018
(Street)

PEMBROKE, D0 HM 08		 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 05/09/2018   A   7,917 A (1) 154,995 D  
Common Shares, $.0033 par value per share               201,676 I By 2015 GRAT
Common Shares, $.0033 par value per share               3,297 I By Limited Liability Company
Depositary Shares (3)               7,000 D  
Depositary Shares (3)               3,000 I By spouse

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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) $ 79.38 05/09/2018   A   7,917     (2) 05/09/2028 Common Shares, $.0033 par value per share 7,917 $ 0 7,917 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, D0 HM 08		   X     Chairman  

Signatures

 /s/ Louis T. Petrillo, Attorney in fact   05/11/2018
**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) Subject to the terms of the restricted share agreement, represents restricted shares that will vest in two equal annual installments on May 9, 2019 and May 9, 2020 respectively.
(2) The stock option will become exercisable in two equal annual installments, with the first installment becoming exercisable on May 9, 2019 and the second installment on May 9, 2020, subject to the applicable award agreement.
(3) Each Depositary Share Represents 1/1,000th interest in a Series F Non-Cumulative Preferred Share.

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