# EDGAR Filing Document

**Accession Number:** 0000776867
**File Stem:** 0001628280-26-046118
**Filing Date:** 2026-6
**Character Count:** 8858
**Document Hash:** 513e5a16f0d803e794d4662455efd479
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001628280-26-046118.hdr.sgml**: 20260630

**ACCESSION NUMBER**: 0001628280-26-046118

**CONFORMED SUBMISSION TYPE**: 11-K

**PUBLIC DOCUMENT COUNT**: 20

**CONFORMED PERIOD OF REPORT**: 20251231

**FILED AS OF DATE**: 20260630

**DATE AS OF CHANGE**: 20260629

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** WHITE MOUNTAINS INSURANCE GROUP LTD
- **CENTRAL INDEX KEY:** 0000776867
- **STANDARD INDUSTRIAL CLASSIFICATION:** FIRE, MARINE & CASUALTY INSURANCE [6331]
- **ORGANIZATION NAME:** 02 Finance
- **EIN:** 942708455
- **STATE OF INCORPORATION:** D0
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** 11-K
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-08993
- **FILM NUMBER:** 261137721

**BUSINESS ADDRESS:**
- **STREET 1:** 23 SOUTH MAIN STREET
- **STREET 2:** SUITE 3B
- **CITY:** HANOVER
- **STATE:** NH
- **ZIP:** 03755
- **BUSINESS PHONE:** 603 640 2200

**MAIL ADDRESS:**
- **STREET 1:** 23 SOUTH MAIN STREET
- **STREET 2:** SUITE 3B
- **CITY:** HANOVER
- **STATE:** NH
- **ZIP:** 03755

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** WHITE MOUNTAINS INSURANCE GROUP INC
- **DATE OF NAME CHANGE:** 19990603

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** FUND AMERICAN ENTERPRISES HOLDINGS INC
- **DATE OF NAME CHANGE:** 19920703

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** FUND AMERICAN COMPANIES INC
- **DATE OF NAME CHANGE:** 19920701

?xml version='1.0' encoding='ASCII'? wtm-20260630

**SECURITIES AND EXCHANGE COMMISSION**

**Washington, D.C. 20549**

**_________________**

**FORM 11-K**

(Mark One)

**&nbsp;&nbsp;&nbsp;&nbsp;ANNUAL REPORT PURSUANT TO SECTION 15(D) OF THE Securities EXCHANGE ACT OF 1934**

&nbsp;&nbsp;&nbsp;&nbsp;For the fiscal year ended December 31, 2025

OR

□&nbsp;&nbsp;&nbsp;&nbsp;**TRANSITION REPORT PURSUANT TO SECTION 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934**

**&nbsp;&nbsp;&nbsp;&nbsp;**For the transition period from ____________ to ______________

**Commission file number**: 1-8993

A. &nbsp;&nbsp;&nbsp;&nbsp;Full title of the plan and the address of the plan, if different from that of the issuer named

&nbsp;&nbsp;&nbsp;&nbsp;below:

&nbsp;&nbsp;&nbsp;&nbsp;**White Mountains Retirement Plan**

B. &nbsp;&nbsp;&nbsp;&nbsp;Name of issuer of the securities held pursuant to the plan and the address of its principal

&nbsp;&nbsp;&nbsp;&nbsp;executive office:

&nbsp;&nbsp;&nbsp;&nbsp;**White Mountains Insurance Group, Ltd.**

**&nbsp;&nbsp;&nbsp;&nbsp;23 South Main Street, Suite 3B**

**&nbsp;&nbsp;&nbsp;&nbsp;Hanover, NH 03755**

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**REQUIRED INFORMATION**

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;1.Not applicable.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;2.Not applicable.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;3.Not applicable.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;4.The White Mountains Retirement Plan (the "Plan") is subject to the requirements of the Employee Retirement Income Security Act of 1974 ("ERISA"). Pursuant to Section 103 of ERISA and the regulations thereunder, the Plan is not required to include an opinion of an independent qualified public accountant because the Plan is eligible to file as a small plan under the applicable Form 5500 rules and satisfies the conditions for the small plan audit waiver. Attached hereto is a copy of the Plan's Summary Annual Report and Schedule I to the Form 5500 that the Plan has filed with the Employee Benefits Security Administration.

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**Summary Annual Report and Schedule I to the Form 5500**

**SUMMARY ANNUAL REPORT FOR**

**WHITE MOUNTAINS RETIREMENT PLAN**

This is a summary of the annual report Form 5500 Annual Return/Report of Employee Benefit Plan of White Mountains Retirement Plan and Employer Identification Number 57-1163892/Plan Number 001 for the plan year 01/01/2025 through 12/31/2025. The Form 5500 annual report has been filed with the Employee Benefits Security Administration, as required under the Employee Retirement Income Security Act of 1974 (ERISA). Your plan is a single employer, defined contribution plan with the following characteristics: profit sharing, ERISA section 404(c), partial participant-directed account, code section 401(k) feature, code section 401(m) arrangement, ESOP, 401(k) or 403(b) plan that provides for automatic enrollment, total or partial participant-directed account, member of a controlled group.

**Basic Financial Statement**

Benefits under the plan are provided by a trust fund. Plan expenses were $763,201. These expenses included $1,324 in administrative expenses and $761,877 in benefits paid to participants and beneficiaries, and $0 in other expenses. A total of 95 persons were participants in or beneficiaries of the plan at the end of the plan year, although not all of these persons had yet earned the right to receive benefits.

The value of plan assets, after subtracting liabilities of the plan, was $56,845,596 as of the end of the plan year, compared to $47,599,790 as of the beginning of the plan year. During the plan year the plan experienced a change in its net assets of $9,245,806. This change includes unrealized appreciation or depreciation in the value of plan assets; that is, the difference between the value of the plan's assets at the end of the year and the value of the assets at the beginning of the year or the cost of assets acquired during the year. The plan had total income of $10,009,007, including employer contributions of $1,169,874, employee contributions of $1,570,203 and earnings from investments of $7,254,335.

**Information Regarding Plan Assets**

The U.S. Department of Labor's regulations require that an independent qualified public accountant audit the plan's financial statements unless certain conditions are met for the audit requirement to be waived. This plan met the audit waiver conditions for the plan year beginning 01/01/2025 and therefore has not had an audit performed.

The plan's assets were held in individual participant accounts with investments directed by participants and beneficiaries and with account statements from regulated financial institutions furnished to the participant or beneficiary at least annually, qualifying employer securities and loans to participants and other qualifying assets.

General information regarding the audit waiver conditions applicable to the plan can be found on the U.S. Department of Labor Web site at https://www.dol.gov/agencies/ebsa under the heading "Frequently Asked Questions."

**Your Rights to Additional Information**

You have the right to receive a copy of the full annual report, or any part thereof, on request. To obtain a copy of the full annual report, or any part thereof, write or call the office of Human Resource Department, who is a representative of the plan administrator, at 23 South Main Street Suite 3B, Hanover, NH 03755 and phone number, 603-640-2200. The charge to cover copying costs will be $5.00 for the full annual report, or $0.25 per page for any part thereof.

You also have the right to receive from the plan administrator, on request and at no charge, a statement of the assets and liabilities of the plan and accompanying notes, or a statement of income and expenses of the plan and accompanying notes, or both. If you request a copy of the full annual report from the plan administrator, these two statements and accompanying notes will be included as part of that report. The charge to cover copying costs given above does not include a charge for the copying of these portions of the report because these portions are furnished without charge.

You also have the legally protected right to examine the annual report at the main office of the plan: 23 South Main Street Suite 3B, Hanover, NH 03755, and at the U.S. Department of Labor in Washington, D.C., or to obtain a copy from the U.S. Department of Labor upon payment of copying costs. Requests to the Department should be addressed to: Public Disclosure Room, Room N-1513, Employee Benefits Security Administration, U.S. Department of Labor, 200 Constitution Avenue, N.W., Washington, D.C. 20210. The annual report is also available online at the Department of Labor website www.efast.dol.gov.

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![Picture1.jpg](wtm-20260630_g1.jpg)

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![Picture3.jpg](wtm-20260630_g2.jpg)

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**SIGNATURES**

&nbsp;&nbsp;&nbsp;&nbsp;*The Plan*. Pursuant to the requirements of the Securities Exchange Act of 1934, the trustees (or other persons who administer the employee benefit plan) have duly caused this annual report to be signed on its behalf by the undersigned hereunto duly authorized.

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| | | |
|:---|:---|:---|
|  | WHITE MOUNTAINS RETIREMENT PLAN | WHITE MOUNTAINS RETIREMENT PLAN |
| DATED: June 29, 2026 | By: | <br><u>/s/ Wesley C. Bell</u> <br>&nbsp;&nbsp;&nbsp;&nbsp;<br>Wesley C. Bell<br> *Authorized Representative* |

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