UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

Current Report Pursuant to Section 13 or 15(d)

of the Securities Exchange Act of 1934

September 4, 2025

Date of Report (Date of earliest event reported)

Arch Capital Group Ltd.

(Exact name of registrant as specified in its charter)

Bermuda

001-16209

98-0374481

(State or other
jurisdiction of
incorporation or
organization)

(Commission File Number)

(I.R.S. Employer
Identification No.)

Waterloo House, Ground Floor, 100 Pitts Bay Road, Pembroke HM 08, Bermuda

(Address of principal executive offices) (Zip Code)

Registrant’s telephone number, including area code:

(441) 278-9250

N/A

(Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below):

☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Exchange Act:

Title of each class

Trading Symbol (s)

Name of each exchange on which registered

Common shares, $0.0011 par value per share

ACGL

NASDAQ

Stock Market

Depositary shares, each representing a 1/1,000th interest in a 5.45% Series F preferred share

ACGLO

NASDAQ

Stock Market

Depositary shares, each representing a 1/1,000th interest in a 4.55% Series G preferred share

ACGLN

NASDAQ

Stock Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. o

ITEM 8.01 Other Events.

On September 4, 2025, Arch Capital Group Ltd. (the “Company”) increased its authorization for its existing share repurchase program by $2.0 billion, which, as in the past, may be effected from time to time in open market or privately negotiated transactions. After taking into account this increased authorization and recent share repurchases during the third quarter of 2025, approximately $2.3 billion of share repurchases are available under the program as of September 4, 2025. The timing and amount of the repurchase transactions under this program will depend on a variety of factors, including market conditions and corporate and regulatory considerations.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, as amended, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.


	ARCH CAPITAL GROUP LTD.


Date: September 5, 2025	By:	/s/ François Morin
		Name:	François Morin
		Title:	Executive Vice President, Chief Financial Officer and Treasurer

ARCH CAPITAL GROUP LTD. 8-K