v3.26.3
Segment Information
9 Months Ended
Sep. 30, 2026
Segment Reporting [Abstract]  
Segment Information Segment Information
 
As of September 30, 2026, White Mountains conducted its operations through five reportable segments: (1) Ark/WM Outrigger, (2) Kudu, (3) HG Global, (4) Distinguished and (5) WTM Partners, with its remaining operating businesses, holding companies and other assets included in Other Operations. White Mountains has made its segment determination based on consideration of the following criteria: (i) the nature of the business activities of each of the Company’s subsidiaries and affiliates; (ii) the manner in which the Company’s subsidiaries and affiliates are organized; (iii) the existence of primary managers responsible for specific subsidiaries and affiliates; and (iv) the organization of information provided to the Company’s CODM and the Board of Directors. The Company’s CODM is its Chief Executive Officer. The CODM utilizes each segment’s pre-tax income (loss) in assessing each segment’s performance and allocating resources. Other measures of segment profitability are also reviewed by the CODM. Significant intercompany transactions among White Mountains’s segments have been eliminated herein.
White Mountains consolidates its segregated account of Outrigger Re Ltd., WM Outrigger Re, in its financial statements. WM Outrigger Re exclusively provides reinsurance protection to Ark, and WM Outrigger Re’s quota share reinsurance agreement with GAIL eliminates in White Mountains’s consolidated financial statements. As a result, WM Outrigger Re is aggregated with Ark within the Ark/WM Outrigger segment.
On September 2, 2025, White Mountains completed the Distinguished Transaction. As a result, White Mountains began consolidating Distinguished in its financial statements on September 2, 2025. See Note 2 — “Significant Transactions.”
In the second quarter of 2026, WTM Partners completed the acquisitions of Hawkeye Electric and Basesix. As a result, WTM Partners is presented as a separate reportable segment. The CODM assesses the performance of WTM Partners’s operating companies and allocates resources in the aggregate to the WTM Partners segment. Prior period amounts have been reclassified to conform to the current period’s presentation. See Note 2 — “Significant Transactions.”
On December 5, 2025, White Mountains completed the Bamboo Sale Transaction. As a result, White Mountains deconsolidated the Bamboo Group on December 5, 2025, and Bamboo is no longer a reportable segment. Through December 5, 2025, Bamboo’s results of operations are presented within the Bamboo segment. White Mountains’s noncontrolling equity interest in the Bamboo SPV is accounted for at fair value in other long-term investments within Other Operations. See Note 2 — “Significant Transactions.”
The following tables present White Mountains’s pre-tax financial results by segment for the three and nine months ended September 30, 2026 and 2025:
Ark/WM OutriggerOther OperationsTotal
MillionsArkWM Outrigger Re
Kudu
HG GlobalDistinguishedWTM Partners
Three Months Ended September 30, 2026
Earned insurance premiums (1)
$509.6 $(.8)$— $8.6 $— $— $.3 $517.7 
Net investment income (2)
27.2 .6 20.7 7.9 .7 — 13.5 70.6 
Net realized and unrealized
   investment gains (losses)
(40.3)— (25.7)(28.8)— — 25.4 (69.4)
Net realized and unrealized investment
   gains (losses) from investment in
   MediaAlpha
— — — — — — (53.6)(53.6)
Interest income from BAM Surplus Notes— — — 6.8 — — — 6.8 
Change in fair value of BAM Surplus Notes— — — (16.1)— — — (16.1)
Commission and fee revenues (1)
— — — — 55.2 — 4.1 59.3 
Product and services revenues— — — — — 106.8 14.3 121.1 
Other revenues (1) (2)
4.5 — — .1 .1 — — 4.7 
     Total revenues501.0 (.2)(5.0)(21.5)56.0 106.8 4.0 641.1 
Loss and LAE (3)
230.1 — — — — — .3 230.4 
Insurance acquisition expenses (3)
113.4 (.3)— 2.1 — — .1 115.3 
Cost of sales— — — — — 84.1 7.7 91.8 
Broker commission expenses— — — — 22.0 — — 22.0 
Amortization of other intangible assets (4)
— — — — 6.4 5.1 1.0 12.5 
General and administrative expenses (3) (4) (5)
59.5 — 2.9 .4 36.9 15.0 26.9 141.6 
Change in fair value of contingent consideration30.0 — — — — — — 30.0 
Interest expense4.2 — 7.4 3.8 3.4 1.2 .7 20.7 
     Total expenses437.2 (.3)10.3 6.3 68.7 105.4 36.7 664.3 
Pre-tax income (loss)$63.8 $.1 $(15.3)$(27.8)$(12.7)$1.4 $(32.7)$(23.2)
(1) Other Operations’s earned insurance premiums and commission and fee revenues are included in other revenues in the consolidated statement of operations.
(2) Distinguished’s net investment income is included in other revenues in the consolidated statement of operations.
(3) Other Operations’s loss and LAE and insurance acquisition expenses are included in general and administrative expenses in the consolidated statement of operations.
(4) Amortization of other intangible assets is included in general and administrative expenses in the consolidated statement of operations.
(5) Ark’s general and administrative expenses include $40.4 of other underwriting expenses.
Ark/WM Outrigger
MillionsArkWM Outrigger ReKuduHG Global
Distinguished (1)
WTM Partners
Bamboo
Other OperationsTotal
Three Months Ended September 30, 2025
Earned insurance premiums (2)
$498.6 $43.6 $— $7.5 $— $— $5.2 $2.9 $557.8 
Net investment income (3)
24.8 2.4 18.0 7.0 .2 — .6 6.2 59.2 
Net realized and unrealized
   investment gains (losses) (3)
17.8 — 36.1 7.2 — — .2 14.9 76.2 
Net realized and unrealized investment
   gains (losses) from investment in
   MediaAlpha
— — — — — — — 7.7 7.7 
Interest income from BAM Surplus Notes— — — 7.5 — — — — 7.5 
Commission and fee revenues (2)
— — — — 14.1 — 63.9 4.3 82.3 
Product and services revenues— — — — — 54.0 — 14.8 68.8 
Other revenues (2) (3)
2.3 — .3 .1 — — 1.5 .5 4.7 
     Total revenues543.5 46.0 54.4 29.3 14.3 54.0 71.4 51.3 864.2 
Loss and LAE (4)
252.4 2.2 — — — — 3.3 .6 258.5 
Insurance acquisition expenses (4)
92.4 14.4 — 2.0 — — 2.0 1.0 111.8 
Cost of sales— — — — — 47.1 — 8.2 55.3 
Broker commission expenses
— — — — 5.5 — 21.5 — 27.0 
Amortization of other intangible assets (5)
— — — — — 2.5 4.0 1.3 7.8 
General and administrative expenses (4) (5) (6)
61.7 — 4.7 1.0 10.2 5.3 22.8 63.3 169.0 
Change in fair value of contingent
   consideration
36.1 — — — — — — — 36.1 
Interest expense4.4 — 6.1 4.3 1.3 .3 2.8 .7 19.9 
     Total expenses447.0 16.6 10.8 7.3 17.0 55.2 56.4 75.1 685.4 
Pre-tax income (loss)$96.5 $29.4 $43.6 $22.0 $(2.7)$(1.2)$15.0 $(23.8)$178.8 
(1) Distinguished’s results are from September 2, 2025, the date of acquisition, through September 30, 2025.
(2) Other Operations’s earned insurance premiums and commission and fee revenues are included in other revenues in the consolidated statement of operations.
(3) Net investment income and net realized and unrealized investment gains (losses) for both Bamboo and Distinguished are included in other revenues in the consolidated statement of operations.
(4) Other Operations’s loss and LAE and insurance acquisition expenses are included in general and administrative expenses in the consolidated statement of operations.
(5) Amortization of other intangible assets is included in general and administrative expenses in the consolidated statement of operations.
(6) Ark’s general and administrative expenses include $33.6 of other underwriting expenses.
Ark/WM OutriggerOther Operations
MillionsArkWM Outrigger Re
Kudu
HG Global
Distinguished
WTM Partners (1)
Total
Nine Months Ended September 30, 2026
Earned insurance premiums (2)
$1,256.1 $2.7 $— $24.0 $— $— $4.4 $1,287.2 
Net investment income (3)
81.5 3.0 60.5 23.4 2.0 — 42.5 212.9 
Net realized and unrealized
   investment gains (losses)
(42.6)(.1)66.0 (36.0)— — 104.7 92.0 
Net realized and unrealized investment
   gains (losses) from investment in
   MediaAlpha
— — — — — — (60.4)(60.4)
Interest income from BAM Surplus Notes— — — 20.6 — — — 20.6 
Change in fair value of BAM Surplus Notes— — — (16.1)— — — (16.1)
Commission and fee revenues (2)
— — — — 151.4 — 11.5 162.9 
Product and services revenues— — — — — 243.3 41.8 285.1 
Net gain on sale of the Bamboo Group
— — — — — — 2.4 2.4 
Other revenues (2) (3)
16.1 — .4 .2 .3 — (.1)16.9 
     Total revenues1,311.1 5.6 126.9 16.1 153.7 243.3 146.8 2,003.5 
Loss and LAE (4)
612.2 .2 — — — — .7 613.1 
Insurance acquisition expenses (4)
314.7 .9 — 6.3 — — 1.7 323.6 
Cost of sales— — — — — 192.8 21.8 214.6 
Broker commission expenses— — — — 62.5 — — 62.5 
Amortization of other intangible assets (5)
— — .1 — 20.2 7.6 2.9 30.8 
General and administrative expenses (4) (5) (6)
151.4 — 11.7 5.3 101.3 37.8 112.6 420.1 
Change in fair value of contingent
   consideration
71.7 — — — — — — 71.7 
Interest expense12.4 — 21.7 11.1 10.5 2.1 2.0 59.8 
     Total expenses1,162.4 1.1 33.5 22.7 194.5 240.3 141.7 1,796.2 
Pre-tax income (loss)$148.7 $4.5 $93.4 $(6.6)$(40.8)$3.0 $5.1 $207.3 
(1) WTM Partners includes the results of Basesix from April 1, 2026, the date of its acquisition, through September 30, 2026, and Hawkeye Electric from May 1, 2026, the date of its acquisition, through September 30, 2026.
(2) Other Operations’s earned insurance premiums and commission and fee revenues are included in other revenues in the consolidated statement of operations.
(3) Distinguished’s net investment income is included in other revenues in the consolidated statement of operations.
(4) Other Operations’s loss and LAE and insurance acquisition expenses are included in general and administrative expenses in the consolidated statement of operations.
(5) Amortization of other intangible assets is included in general and administrative expenses in the consolidated statement of operations.
(6) Ark’s general and administrative expenses include $111.6 of other underwriting expenses.
Ark/WM OutriggerOther Operations
MillionsArkWM Outrigger Re
Kudu
HG Global
Distinguished (1)
WTM Partners (2)
BambooTotal
Nine Months Ended September 30, 2025
Earned insurance premiums (3)
$1,201.7 $62.7 $— $22.8 $— $— $21.7 $19.1 $1,328.0 
Net investment income (4)
70.2 6.8 56.7 19.8 .2 — 2.0 24.5 180.2 
Net realized and unrealized
   investment gains (losses) (4)
98.5 (.1)80.9 20.3 — — .5 49.5 249.6 
Net realized and unrealized investment
   gains (losses) from investment in
   MediaAlpha
— — — — — — — 1.6 1.6 
Interest income from BAM Surplus Notes
— — — 22.5 — — — — 22.5 
Commission and fee revenues (3)
— — — — 14.1 — 167.2 12.4 193.7 
Product and services revenues— — — — — 96.8 — 41.9 138.7 
Other revenues (3) (4)
10.8 — 1.0 .2 — — 3.9 1.0 16.9 
     Total revenues1,381.2 69.4 138.6 85.6 14.3 96.8 195.3 150.0 2,131.2 
Loss and LAE (5)
628.0 24.1 — — — — 15.9 18.8 686.8 
Insurance acquisition expenses (5)
272.0 15.5 — 5.9 — — 8.0 7.0 308.4 
Cost of sales— — — — — 82.3 — 22.9 105.2 
Broker commission expenses— — — — 5.5 — 56.8 — 62.3 
Amortization of other intangible assets (6)
— — .2 — — 2.5 12.0 3.4 18.1 
General and administrative expenses (5) (6) (7)
154.0 .1 12.1 2.6 10.2 14.7 57.4 141.1 392.2 
Change in fair value of contingent
   consideration
74.2 — — — — — — — 74.2 
Interest expense12.9 — 18.6 13.4 1.3 .6 7.8 1.7 56.3 
     Total expenses1,141.1 39.7 30.9 21.9 17.0 100.1 157.9 194.9 1,703.5 
Pre-tax income (loss)$240.1 $29.7 $107.7 $63.7 $(2.7)$(3.3)$37.4 $(44.9)$427.7 
(1) Distinguished’s results are from September 2, 2025, the date of acquisition, through September 30, 2025.
(2) WTM Partners includes the results of Enterprise Solutions from April 1, 2025, the date of acquisition, through September 30, 2025.
(3) Other Operations’s earned insurance premiums and commission and fee revenues are included in other revenues in the consolidated statement of operations.
(4) Net investment income and net realized and unrealized investment gains (losses) for both Bamboo and Distinguished are included in other revenues in the consolidated statement of operations.
(5) Other Operations’s loss and LAE and insurance acquisition expenses are included in general and administrative expenses in the consolidated statement of operations.
(6) Amortization of other intangible assets is included in general and administrative expenses in the consolidated statement of operations.
(7) Ark’s general and administrative expenses include $108.4 of other underwriting expenses.

The following tables present White Mountains’s revenues from external customers by country for the three and nine months ended September 30, 2026 and 2025:
Three Months Ended September 30, 2026
MillionsUnited StatesUnited KingdomBermudaOtherTotal
Earned insurance premiums$.3 $329.0 $188.4 $— $517.7 
Commission and fee revenues55.2 — — 4.1 59.3 
Product and service revenues121.1 — — — 121.1 
Total$176.6 $329.0 $188.4 $4.1 $698.1 

Three Months Ended September 30, 2025
MillionsUnited StatesUnited KingdomBermudaOtherTotal
Earned insurance premiums$5.2 $335.2 $217.4 $— $557.8 
Commission and fee revenues78.0 — — 4.3 82.3 
Product and service revenues68.8 — — — 68.8 
Total$152.0 $335.2 $217.4 $4.3 $708.9 
Nine Months Ended September 30, 2026
MillionsUnited StatesUnited KingdomBermudaOtherTotal
Earned insurance premiums$.7 $797.8 $488.7 $— $1,287.2 
Commission and fee revenues151.4 — — 11.5 162.9 
Product and service revenues285.1 — — — 285.1 
Total$437.2 $797.8 $488.7 $11.5 $1,735.2 

Nine Months Ended September 30, 2025
MillionsUnited StatesUnited KingdomBermudaOtherTotal
Earned insurance premiums$21.7 $779.7 $526.6 $— $1,328.0 
Commission and fee revenues181.3 — — 12.4 193.7 
Product and service revenues138.7 — — — 138.7 
Total$341.7 $779.7 $526.6 $12.4 $1,660.4 

The following table presents White Mountains’s balance sheet information by segment as of September 30, 2026 and December 31, 2025:
Millions
Selected Balance Sheet Data
Ark/WM OutriggerKuduHG Global
Distinguished
WTM PartnersOther
Operations
Total
September 30, 2026
Total investments$3,817.5 $1,440.0 $748.3 $70.6 $.6 $2,203.9 
(1)
$8,280.9 
Total assets$7,147.3 $1,478.2 $1,205.7 $720.9 $441.5 $2,369.0 
(2) (3)
$13,362.6 
Total liabilities$5,459.8 $473.5 $566.6 
(2)
$317.4 $193.6 $125.4 
(3)
$7,136.3 
Redeemable noncontrolling interests
$— $— $— $131.5 $— $— $131.5 
Total White Mountains’s
   common shareholders’ equity
$1,197.6 $863.9 $664.2 
(2)
$196.0 $192.5 $2,238.9 
(2)
$5,353.1 
Nonredeemable noncontrolling interests
$489.9 $140.8 $(25.1)$76.0 $55.4 $4.7 $741.7 
December 31, 2025
Total investments$3,926.5 $1,313.3 $784.2 $94.0 $.5 $2,205.4 
(1)
$8,323.9 
Total assets$6,354.1 $1,402.3 $1,236.8 $735.4 $182.4 $2,395.5 
(2) (3)
$12,306.5 
Total liabilities$4,528.5 $446.9 $499.5 
(2)
$307.1 $91.4 $178.0 
(3)
$6,051.4 
Redeemable noncontrolling interests$— $— $— $131.5 $— $— $131.5 
Total White Mountains’s
   common shareholders’ equity
$1,360.4 $814.2 $755.7 
(2)
$223.1 $60.0 $2,212.0 
(2)
$5,425.4 
Nonredeemable noncontrolling interests
$465.2 $141.2 $(18.4)$73.7 $31.0 $5.5 $698.2 
(1) Total investments as of September 30, 2026 and December 31, 2025 exclude $1.5 and $1.0 related to an Other Operating Business that was reclassified to assets held for sale. See Note 19 — “Held for Sale.”
(2) HG Global preferred dividends payable to White Mountains’s subsidiaries are eliminated in White Mountains’s consolidated financial statements. For segment reporting, the HG Global preferred dividends payable to White Mountains’s subsidiaries included within the HG Global segment are eliminated against the offsetting receivable included within Other Operations and therefore added back to White Mountains’s common shareholders’ equity within the HG Global segment. As of September 30, 2026 and December 31, 2025, the HG Global preferred dividends payable to White Mountains’s subsidiaries were $486.8 and $527.2.
(3) Amounts include held for sale balances. See Note 19 — “Held for Sale.”