White Mountains Insurance (WTM)

BAMBOO IDE8 INSURANCE SERVICES, LLC • IDE8 RE CELL 1, INC. • IDE8 RE CELL 2 INC. • IDE8 RE INC. • ARK INSURANCE HOLDINGS LIMITED • GROUP ARK INSURANCE HOLDINGS LIMITED • GROUP ARK INSURANCE LIMITED • HG GLOBAL LTD • HG HOLDINGS LTD • HG RE LTD ...

IRS number

942708455

WTM stock data

1M 3M 6M 1Y

Latest filings (excl ownership)

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6 Nov 25

White Mountains Reports Third Quarter Results

6 Nov 25

8-K

Entry into a Material Definitive Agreement

Departure of Directors or Certain Officers

2 Sep 25

N-PX

Annual report of proxy voting record

7 Aug 25

White Mountains Reports Second Quarter Results

7 Aug 25

8-K

BroadStreet Partners Completes Strategic Investment

Latest ownership filings

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David Allen Tanner

10 Nov 25

SCHEDULE 13G/A

Beneficial ownership report (amended)

7 Nov 25

13F-HR

Quarterly holdings report by institutional manager

White Mountains Insurance Group LTD

7 Aug 25

11-K

Annual report of employee stock purchases

Financial summary

Financial statements Chart WTM financial data

Quarter (USD)	Sep 25	Jun 25	Mar 25	Dec 24
Revenue
Cost of revenue
Operating income
Operating margin
Net income
Net profit margin
Cash on hand
Change in cash
Diluted EPS

Annual (USD)	Dec 24	Dec 23	Dec 22	Dec 21
Revenue
Cost of revenue
Operating income
Operating margin
Net income
Net profit margin
Cash on hand
Change in cash
Diluted EPS

Financial data from company earnings reports.

Institutional ownership, Q4 2024

WTM institutional ownership history Ownership history

89.8% owned by funds/institutions

13F holders	Current	Prev Q	Change
Total holders	318	301	+5.6%
Opened positions	39	29	+34.5%
Closed positions	22	32	-31.3%
Increased positions	110	105	+4.8%
Reduced positions	83	83	–

13F shares	Current	Prev Q	Change
Total value	4.11 tn	3.46 tn	+18.6%
Total shares	2.29 mm	2.22 mm	+3.5%
Total puts	0.00	0.00
Total calls	0.00	0.00
Total put/call ratio	–	–	–

Largest owners	Shares	Value	Change
Vanguard	251.74 k	$489.65 bn	+0.4%
MS Morgan Stanley	177.69 k	$345.62 bn	-0.8%
Dimensional Fund Advisors	157.40 k	$306.14 bn	-0.7%
BlackRock	118.48 k	$230.46 bn	+2.9%
Fuller & Thaler Asset Management	114.08 k	$221.89 bn	-6.7%
River Road Asset Management	112.42 k	$218.65 bn	-4.9%
Boston Partners	85.45 k	$165.82 bn	+0.4%
Wallace Capital Management	80.16 k	$155.91 bn	-2.7%
London Co Of Virginia	69.27 k	$134.73 bn	-0.8%
T. Rowe Price Investment Management	57.76 k	$112.34 mm	+0.1%

Largest transactions	Shares	Bought/sold	Change
Cooke & Bieler	34.07 k	+34.07 k	NEW
RJF Raymond James Financial	32.47 k	+32.47 k	NEW
Norges Bank	30.67 k	+30.67 k	NEW
Proficio Capital Partners	23.35 k	+23.35 k	NEW
Raymond James & Associates	0.00	-21.74 k	EXIT
FMR	697.00	-21.50 k	-96.9%
Scout Investments	0.00	-12.84 k	EXIT
Neuberger Berman	45.44 k	+12.33 k	+37.2%
WCM Investment Management	11.65 k	+11.65 k	NEW
Wellington Management	49.93 k	-10.75 k	-17.7%

Data from 13F filings, for the last complete 13F reporting period. For most recent data, click the ownership history button. Values as filed, not updated for current price. Long positions only.

Recent insider trades

WTM insider ownership history Insider history

Date	Owner	Security	Transaction	Code	Indirect	10b5-1	#Shares	#Remaining
10 Nov 25	Tanner David Allen	Common Shares	Gift	Dispose G	No	No	4	2,104
22 May 25	Carlson Peter M	Common Shares	Grant	Acquire A	No	No	150	717
22 May 25	Reid Tarlton Campbell	Common Shares	Grant	Acquire A	No	No	150	15,490
22 May 25	Choksi Mary C	Common Shares	Grant	Acquire A	No	No	150	1,858
22 May 25	Gelston Philip A	Common Shares	Grant	Acquire A	No	No	150	1,733

Data from 3, 4 and 5 filings. Values as filed, not updated for current price.

News

From Benzinga Pro

White Mountains Insurance, Rumble, Mesoblast And Other Big Stocks Moving Higher On Friday

3 Oct 25

White Mountains Sells Majority Stake In Bamboo In $1.75 Billion Deal

3 Oct 25

White Mountains Insurance Group traded higher after announcing sale of controlling interest in Bamboo for $1.75 billion.

White Mountains Insurance Agrees To Sell Controlling Stake In Bamboo To Funds Advised By CVC Capital Partners For $1.75B; White Mountains To Maintain 15% Stake In Bamboo

3 Oct 25

HAMILTON, Bermuda, Oct. 3, 2025 /PRNewswire/ -- White Mountains Insurance Group, Ltd. (NYSE: WTM) ("White Mountains") announced today that it has signed a definitive agreement to sell a controlling interest in

Is White Mountains Insurance Gaining or Losing Market Support?

15 Aug 25

Press releases

From Benzinga Pro

White Mountains to Sell Bamboo to CVC

3 Oct 25