White Mountains Insurance Group (WTM) reports $195.5M in 13F holdings

Rhea-AI Filing Summary

White Mountains Insurance Group Ltd filed a Form 13F reporting its institutional holdings. The filing lists a Form 13F Information Table Value Total of $195,529,923 and an Information Table Entry Total of 1. The report is signed by Michaela J. Hildreth, Managing Director and Chief Accounting Officer, dated 08-11-2025. The filing indicates no other included managers and is marked as a 13F Holdings Report.

The Securities and Exchange Commission has not necessarily reviewed the information in this filing and has not determined if it is accurate and complete.
The reader should not assume that the information is accurate and complete.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
FORM 13F

FORM 13F COVER PAGE

OMB APPROVAL

OMB Number:			3235-0006
Estimated average burden
hours per response:			23.8

Report for the Calendar Year or Quarter Ended: 06-30-2025

Check here if Amendment		Amendment Number:
This Amendment (Check only one.):		is a restatement.
		adds new holdings entries.

Institutional Investment Manager Filing this Report:
Name:	WHITE MOUNTAINS INSURANCE GROUP LTD
Address:	23 South Main Street
	Suite 3B
	Hanover, NH 03755
Form 13F File Number:	028-01681
CRD Number (if applicable):
SEC File Number (if applicable):

The institutional investment manager filing this report and the person by whom it is signed hereby represent that the person signing the report is authorized to submit it, that all information contained herein is true, correct and complete, and that it is understood that all required items, statements, schedules, lists, and tables, are considered integral parts of this form.

Person Signing this Report on Behalf of Reporting Manager:
Name:		Michaela J. Hildreth
Title:		Managing Director and Chief Accounting Officer
Phone:		603-640-2200
Signature, Place, and Date of Signing:
/s/ Michaela J. Hildreth			Boston, MA	08-11-2025
[Signature]			[City, State]	[Date]

Report Type (Check only one.):
X	13F HOLDINGS REPORT. (Check here if all holdings of this reporting manager are reported in this report.)
	13F NOTICE. (Check here if no holdings reported are in this report, and all holdings are reported by other reporting manager(s).)
	13F COMBINATION REPORT. (Check here if a portion of the holdings for this reporting manager are reported in this report and a portion are reported by other reporting manager(s).)

Form 13F Summary Page
	Report Summary:
	Number of Other Included Managers:		0
	Form 13F Information Table Entry Total:		1
	Form 13F Information Table Value Total:		195,529,923
			(round to nearest dollar)

List of Other Included Managers:

Provide a numbered list of the name(s) and Form 13F file number(s) of all institutional investment managers with respect to which this report is filed, other than the manager filing this report.

[If there are no entries in this list, state "NONE" and omit the column headings and list entries.]

NONE

FAQ

What does White Mountains (WTM) report in this Form 13F filing?

It reports institutional holdings valued at $195,529,923 across 1 entry. The filing is a Form 13F Holdings Report signed by Michaela J. Hildreth on 08-11-2025, and shows no other included managers.

Who signed White Mountains' 13F and when was it signed?

The report is signed by Michaela J. Hildreth, Managing Director and Chief Accounting Officer. The signature block shows Boston, MA and a signing date of 08-11-2025 on the cover information provided.

How many holdings entries and total value does the filing show for WTM?

The filing lists 1 Form 13F information table entry and a total value of $195,529,923. These figures appear on the Form 13F Summary Page as the entry total and value total, respectively.

Does the 13F filing list any other included managers for White Mountains?

No — the filing indicates zero other included managers. The List of Other Included Managers section explicitly states NONE, showing this report covers the reporting manager's holdings alone.