White Mountains (WTM) director receives 135-share annual equity award

Rhea-AI Filing Summary

CAMPBELL REID TARLTON reported acquisition or exercise transactions in this Form 4 filing.

WHITE MOUNTAINS INSURANCE GROUP LTD director Campbell Reid Tarlton received an equity award of common shares. He was granted 135 common shares as an annual director share award at no purchase price, which is a stock-based component of his board compensation.

After this grant, Tarlton directly holds 10,575 common shares. In addition, he has an indirect holding of 119 common shares through a 401(k) account. The filing does not report any open-market buys or sales, only this compensation-related share award and existing holdings.

Insider Trade Summary

2 transactions reported

Mixed 2 txns

Insider CAMPBELL REID TARLTON

Role null

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

Holdings After Transaction: Common Shares — 10,575 shares (Direct, null); Common Shares — 119 shares (Indirect, by 401(k))

Footnotes (1)

1. [object Object]

Key Figures

Director share award: 135 shares Award price per share: 0.0000 per share Direct holdings after transaction: 10,575 shares +1 more

4 metrics

Director share award 135 shares Annual director share award, transaction code A

Award price per share 0.0000 per share Grant, award, or other acquisition

Direct holdings after transaction 10,575 shares Common shares held directly after award

Indirect 401(k) holdings 119 shares Common shares held indirectly by 401(k)

Key Terms

Grant, award, or other acquisition, 401(k), Annual Director Share Award, Common Shares

4 terms

Grant, award, or other acquisition financial

"transaction_code_description: Grant, award, or other acquisition"

401(k) financial

"nature_of_ownership: by 401(k)"

A 401(k) is a type of retirement savings plan offered by employers that allows workers to set aside a portion of their paycheck before taxes are taken out. The money saved in a 401(k) can grow over time through investments, helping individuals build funds for their future retirement. It matters to investors because it provides a tax-advantaged way to save and invest for long-term financial security.

Annual Director Share Award financial

"footnote: Annual Director Share Award"

Common Shares financial

"security_title: 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^*

CAMPBELL REID TARLTON

(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	10,575	D
Common Shares								119	I	by 401(k)

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 Campbell Reid Tarlton?

WHITE MOUNTAINS reported that director Campbell Reid Tarlton received 135 common shares as an annual director share award. This Form 4 shows a compensation-related equity grant, not an open-market purchase or sale of WHITE MOUNTAINS stock.

How many WHITE MOUNTAINS (WTM) shares did Campbell Reid Tarlton acquire in this Form 4?

Campbell Reid Tarlton acquired 135 common shares in this filing. The shares were granted at a price of 0.0000 per share as an annual director share award, reflecting stock-based compensation rather than a market transaction in WHITE MOUNTAINS stock.

What are Campbell Reid Tarlton’s WHITE MOUNTAINS (WTM) holdings after this award?

After the award, Campbell Reid Tarlton directly holds 10,575 common shares of WHITE MOUNTAINS. He also has an indirect position of 119 common shares held through a 401(k) account, according to the reported post-transaction share balances in the Form 4.

Does this WHITE MOUNTAINS (WTM) Form 4 show any stock sales by Campbell Reid Tarlton?

The Form 4 does not show any stock sales by Campbell Reid Tarlton. It reports a grant of 135 common shares as an annual director share award and lists his post-transaction direct and indirect holdings in WHITE MOUNTAINS common shares.

Is the Campbell Reid Tarlton transaction in WHITE MOUNTAINS (WTM) an open-market buy?

The transaction is not an open-market buy; it is a grant. The filing classifies the 135-share increase as a “Grant, award, or other acquisition,” reflecting equity compensation granted at no cost to Campbell Reid Tarlton as a director.