White Mountains CAO granted 600 restricted shares

Hildreth Michaela reported acquisition or exercise transactions in this Form 4 filing.

Accepted by SEC EDGAR 02/27/2026 - 11:18 AM EST Learn about SEC filing dates

Rhea-AI Filing Summary

Hildreth Michaela reported acquisition or exercise transactions in this Form 4 filing.

WHITE MOUNTAINS INSURANCE GROUP LTD executive Michaela Hildreth, MD & Chief Accounting Officer, reported receiving a grant of 600 restricted Common Shares on February 25, 2026, at a price of $0.00 per share. The award will vest on January 1, 2029.

After this grant, she directly held 1,825 restricted Common Shares. As of the same date, she also directly held 2,491 Common Shares and indirectly held 20 Common Shares through a 401(k) account.

Insider Trade Summary

Grant/Award: 600 shares

Grant/Award 1 txn

Insider Hildreth Michaela

Role MD & Chief Accounting Officer

Type	Security	Shares	Price	Value
Grant/Award	Common Shares (Restricted)	600	$0.00	$0.00
Holding	Common Shares	--	--	--
Holding	Common Shares	--	--	--

Holdings After Transaction: Common Shares (Restricted) — 1,825 shares (Direct); Common Shares — 2,491 shares (Direct); Common Shares — 20 shares (Indirect, by 401(k))

Footnotes (1)

1. F1. On February 25, 2026, the Reporting Person received a restricted share award of 600 Common Shares, which vests on January 1, 2029.

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

What insider transaction did WHITE MOUNTAINS (WTM) report for Michaela Hildreth?

Michaela Hildreth received a grant of 600 restricted Common Shares on February 25, 2026. The shares were awarded at a price of $0.00 per share and represent equity-based compensation rather than an open-market purchase or sale.

When do Michaela Hildreth’s newly granted WTM restricted shares vest?

The 600 restricted Common Shares granted to Michaela Hildreth vest on January 1, 2029. Until vesting, the award is typically subject to service or other conditions, aligning her compensation with longer-term company performance over several years.

How many WHITE MOUNTAINS (WTM) shares does Michaela Hildreth hold after this Form 4?

Following the February 25, 2026 grant, Michaela Hildreth directly held 1,825 restricted Common Shares and 2,491 Common Shares. She also indirectly held 20 Common Shares through a 401(k) account associated with her employment.

Was the WTM Form 4 transaction a market buy or sell by Michaela Hildreth?

The Form 4 shows a grant or award acquisition, not a market trade. Michaela Hildreth received 600 restricted Common Shares at $0.00 per share as part of her compensation, rather than buying or selling shares on the open market.

How is Michaela Hildreth’s indirect ownership in WHITE MOUNTAINS (WTM) reported?

Indirect ownership is reported through a 401(k) plan. The Form 4 lists 20 Common Shares held indirectly “by 401(k)”, separate from her directly held restricted and unrestricted Common Shares, clarifying different forms of beneficial ownership.

What is Michaela Hildreth’s role at WHITE MOUNTAINS (WTM) in this Form 4?

Michaela Hildreth is identified as an officer of WHITE MOUNTAINS, serving as MD & Chief Accounting Officer. The reported 600-share restricted award represents part of her equity compensation as a senior executive at the company.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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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^*

Hildreth Michaela

(Last) (First) (Middle)

C/O WHITE MOUNTAINS INSURANCE GROUP, LTD

23 SOUTH MAIN STREET, SUITE 3B

(Street)

HANOVER NH 03755

(City) (State) (Zip)

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)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	MD & Chief Accounting Officer

3. Date of Earliest Transaction (Month/Day/Year)
02/25/2026

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

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

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

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 (Restricted)	02/25/2026		A		600	A	$0	1,825(1)	D
Common Shares								2,491	D
Common Shares								20	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. On February 25, 2026, the Reporting Person received a restricted share award of 600 Common Shares, which vests on January 1, 2029.

	Wesley C Bell, by Power of Attorney	02/25/2026
	** 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).
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