White Mountains (NYSE: WTM) expands board to 11 seats
Rhea-AI Filing Summary
WHITE MOUNTAINS INSURANCE GROUP, LTD. (WTM) reported a board change, electing Stephen Klar as a director effective August 26, 2026. The Board of Directors was increased from 10 to 11 members in connection with his election. Klar will serve until the next annual meeting of shareholders and until a successor is elected and qualified or until earlier resignation or removal. He will be compensated under the standard compensatory arrangement for non-employee directors, including a pro-rated cash and common equity retainer for the remainder of the year. The company states there are no arrangements or understandings with other persons regarding his election and that he has no material interest in any related-party transactions requiring disclosure. A press release announcing his election is furnished as Exhibit 99.1.
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8-K Event Classification
2 items: 5.02, 9.01
2 items
Item 5.02
Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers
Governance
Key personnel changes including departures, elections, or appointments of directors and executive officers.
Item 9.01
Financial Statements and Exhibits
Exhibits
Financial statements, pro forma financial information, or exhibit attachments filed with this report.
Key Figures
Board size after election: 11 directors
Board size before election: 10 directors
Trading symbol (NYSE): WTM
+2 more
5 metrics
Board size after election
11 directors
Board of Directors size increased from 10 to 11 upon election of Stephen Klar on August 26, 2026
Board size before election
10 directors
Board size prior to the election of Stephen Klar
Trading symbol (NYSE)
WTM
Common Shares, par value $1.00 per share, listed on the New York Stock Exchange
Trading symbol (Bermuda Stock Exchange)
WTM.BH
Common Shares traded on the Bermuda Stock Exchange under symbol WTM.BH
Date of press release
August 27, 2026
Date of Exhibit 99.1 press release announcing Stephen Klar’s election
Key Terms
non-employee directors, Item 404(a) of Regulation S-K, Inline XBRL
3 terms
non-employee directors financial
"standard compensatory arrangement for non-employee directors, including a pro-rated cash"
Non-employee directors are board members who do not work for the company as salaried employees and usually do not hold day-to-day management roles. They act like outside referees or independent coaches, providing oversight, asking tough questions, and protecting shareholders’ interests; investors care because these directors help ensure management is accountable, reduce conflicts of interest, and influence decisions that affect company strategy and long-term value.
Item 404(a) of Regulation S-K regulatory
"material interest in any transaction required to be disclosed pursuant to Item 404(a) of Regulation S-K"
Inline XBRL technical
"Cover Page Interactive Data File (the cover page XBRL tags are embedded within the Inline XBRL"
Inline XBRL is a file format for financial filings that embeds machine-readable data tags directly inside the human-readable report, so the same document can be read by people and parsed by software. For investors it makes extracting, comparing and verifying financial numbers faster and more reliable—like a grocery list where each item also has a barcode—reducing manual errors and speeding up analysis.
FAQ
What board change did WHITE MOUNTAINS INSURANCE GROUP LTD (WTM) announce?
The company announced that Stephen Klar was elected as a director on August 26, 2026, and that the size of the Board of Directors was increased from 10 to 11 members in connection with his election.
How long will Stephen Klar serve on the WTM board?
Stephen Klar will serve as a director until White Mountains holds its next annual meeting of shareholders and a successor is elected and qualified, or until his earlier resignation or removal, as specified in the disclosure.
How will Stephen Klar be compensated as a WTM director?
Stephen Klar will receive compensation under the company’s standard compensatory arrangement for non-employee directors, including a pro-rated cash and common equity retainer for the remainder of the current year, consistent with the program described in the April 1, 2026 proxy statement.
AI-generated analysis. How Rhea-AI works. Not financial advice.
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
Date of Report (Date of earliest event reported)
(Exact name of registrant as specified in its charter)
(State or other jurisdiction of incorporation or organization) | (Commission file number) | (I.R.S. Employer Identification No.) | ||||||
(Address of principal executive offices)
(603 ) 640-2200
(Registrant’s telephone number, including area code)
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:
Securities registered pursuant to Section 12(b) of the Act:
| Title of each class | Trading Symbol(s) | Name of each exchange on which registered | ||||||||||||
| WTM.BH | Bermuda Stock Exchange | |||||||||||||
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 5.02 Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers.
On August 26, 2026, the Board of Directors (the “Board”) of White Mountains Insurance Group, Ltd. (the “Company”) elected Stephen Klar as a director of the Company. In connection with Mr. Klar’s election, the size of the Board was increased from 10 to 11 persons. Mr. Klar will hold office as a director on the Board until the Company’s next annual meeting of shareholders and until his successor is elected and qualified or until his earlier resignation or removal.
Mr. Klar will receive compensation for his service on the Board in accordance with the Company’s standard compensatory arrangement for non-employee directors, including a pro-rated cash and common equity retainer for the remainder of the current year. A description of the Company’s non-employee director compensation appears under the caption “Director Compensation” in the Company’s Proxy Statement filed with the Securities and Exchange Commission on April 1, 2026.
There are no arrangements or understandings between Mr. Klar and any other persons pursuant to which he was elected as a director. Mr. Klar has no direct or indirect material interest in any transaction required to be disclosed pursuant to Item 404(a) of Regulation S-K.
Our press release announcing Mr. Klar’s election as director is attached as Exhibit 99.1 and incorporated by reference herein.
ITEM 9.01 Financial Statements and Exhibits.
(d) Exhibits
99.1 Press Release, dated as of August 27, 2026
104 Cover Page Interactive Data File (the cover page XBRL tags are embedded within the Inline XBRL document)
2
SIGNATURES
Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized.
| WHITE MOUNTAINS INSURANCE GROUP, LTD. | ||||||||||||||
| August 27, 2026 | By: | /s/ MICHAELA J. HILDRETH Michaela J. Hildreth Managing Director and Chief Accounting Officer | ||||||||||||
3
Exhibit 99.1
 | PRESS RELEASE CONTACT: Rob Seelig (603) 640-2212 | |||||||
Stephen Klar Elected to the White Mountains Board
HAMILTON, Bermuda, August 27, 2026 /PRNewswire/ -- The Board of Directors of White Mountains Insurance Group, Ltd. (NYSE: WTM) has elected Stephen Klar as a director of the Company.
Mr. Klar was formerly the President and a Managing Partner of Wellington Management Group LLP.
CEO Liam Caffrey said, "We are delighted to welcome Steve to our Board of Directors. His extensive experience in the financial services industry will greatly benefit our owners."
About White Mountains
White Mountains is a Bermuda-domiciled financial services holding company traded on the New York Stock Exchange and the Bermuda Stock Exchange under the symbol “WTM” and “WTM.BH”, respectively.