WHITE MOUNTAINS (WTM) director granted 135 common shares in annual award

Rhea-AI Filing Summary

WHITE MOUNTAINS INSURANCE GROUP LTD director Peter M. Carlson received an annual director share award in the form of 135 Common Shares on May 21, 2026. The shares were granted at a price of $0.00 per share as compensation, not as an open-market purchase.

Following this award, Carlson directly holds 852 Common Shares of the company. The filing reports no derivative securities and no sales or disposals, only this grant/award acquisition.

Insider Trade Summary

1 transaction reported

Mixed 1 txn

Insider Carlson Peter M

Role null

Type	Security	Shares	Price	Value
Grant/Award	Common Shares	135	$0.00	--

Holdings After Transaction: Common Shares — 852 shares (Direct, null)

Footnotes (1)

1. [object Object]

Key Figures

Shares granted: 135 Common Shares Grant price: $0.00 per share Shares owned after transaction: 852 Common Shares

3 metrics

Shares granted 135 Common Shares Annual director share award on May 21, 2026

Grant price $0.00 per share Equity compensation grant, not open-market purchase

Shares owned after transaction 852 Common Shares Direct ownership following the award

Key Terms

Annual Director Share Award, Grant, award, or other acquisition, Common Shares

3 terms

Annual Director Share Award financial

"Annual Director Share Award"

Grant, award, or other acquisition financial

"transaction code description is "Grant, award, or other acquisition""

Common Shares financial

"security_title is listed as "Common Shares""

Common shares are the basic units of ownership in a company that give holders a claim on profits and a right to vote on key matters, like electing the board. Think of them as membership cards in a club: they let you share in successes and losses, but in a bankruptcy or liquidation they are paid after creditors and preferred shareholders, so their value can swing more and matters for assessing risk and potential return.

Form 4 Insider Transactions: What Each Field Means →

SEC Form 4

FORM 4

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

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Carlson Peter M

(Last) (First) (Middle)

C/O WHITE MOUNTAINS INSURANCE GROUP, LTD

23 SOUTH MAIN STREET, SUITE 3B

(Street)

HANOVER NEW HAMPSHIRE 03755

(City) (State) (Zip)

UNITED STATES

(Country)

2. Issuer Name and Ticker or Trading Symbol
WHITE MOUNTAINS INSURANCE GROUP LTD [ WTM ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director		10% Owner
	Officer (give title below)		Other (specify below)

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
05/21/2026

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

4. If Amendment, Date of Original Filed (Month/Day/Year)

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	05/21/2026		A		135(1)	A	$0	852	D

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 Securities Underlying Derivative Security (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: 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

Explanation of Responses:

1. Annual Director Share Award

	Wesley C. Bell, by Power of Attorney	05/21/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* 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).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.
* Form 4: SEC 1474 (03-26)

FAQ

What insider transaction did WHITE MOUNTAINS (WTM) report for Peter M. Carlson?

WHITE MOUNTAINS (WTM) reported that director Peter M. Carlson received an award of 135 Common Shares. The Form 4 classifies this as a grant or award acquisition, not an open-market purchase, and it increases his direct holdings to 852 Common Shares.

How many WHITE MOUNTAINS (WTM) shares did Peter M. Carlson receive and at what price?

Peter M. Carlson received 135 Common Shares of WHITE MOUNTAINS (WTM) at $0.00 per share. The zero price indicates this was an equity compensation grant, recorded as a non-derivative acquisition rather than a market transaction or purchase for cash.

What are Peter M. Carlson’s WHITE MOUNTAINS (WTM) holdings after this Form 4 grant?

After the reported grant, Peter M. Carlson directly owns 852 Common Shares of WHITE MOUNTAINS (WTM). This total reflects his position immediately following the 135-share annual director award disclosed in the Form 4, with no derivative securities reported outstanding.

Was the WHITE MOUNTAINS (WTM) Form 4 transaction an open-market buy or a compensation grant?

The WHITE MOUNTAINS (WTM) Form 4 shows a compensation grant, not an open-market buy. The transaction code is “A” for grant, award, or other acquisition, with 135 Common Shares issued at $0.00 per share as an annual director share award.

Does the WHITE MOUNTAINS (WTM) Form 4 for Peter M. Carlson include any share sales?

The WHITE MOUNTAINS (WTM) Form 4 for Peter M. Carlson reports no share sales or disposals. It records only one non-derivative transaction: a grant of 135 Common Shares as an annual director share award, increasing his direct ownership to 852 shares.