White Mountains Insurance Group Ltd: Form 10-Q for the period ended Sep 30, 2025

*The following discussion contains “forward-looking statements.” White Mountains intends statements that are not historical in nature, which are hereby identified as forward-looking statements, to be covered by the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. White Mountains cannot promise that its expectations in such forward-looking statements will turn out to be correct. White Mountains’s actual results could be materially different from and worse than its expectations. See “*FORWARD-LOOKING STATEMENTS” on page 94 for specific important factors that could cause actual results to differ materially from those contained in forward-looking statements.

The following discussion also includes 11 non-GAAP financial measures: (i) Ark’s tangible book value, (ii) Kudu’s earnings before interest, taxes, depreciation and amortization (“EBITDA”), (iii) Kudu’s adjusted EBITDA, (iv) Bamboo’s MGA pre-tax income (loss), (v) Bamboo’s MGA net income (loss), (vi) Bamboo’s MGA EBITDA, (vii) Bamboo’s MGA adjusted EBITDA (viii) Distinguished’s ScaleCo net income (loss), (ix) Distinguished’s ScaleCo EBITDA (x) Distinguished’s ScaleCo adjusted EBITDA and (xi) total consolidated portfolio returns excluding MediaAlpha that have been reconciled from their most comparable GAAP financial measures on page 92. White Mountains believes these measures to be useful in evaluating White Mountains’s financial performance and condition.

RESULTS OF OPERATIONS FOR THE THREE AND NINE MONTHS ENDED SEPTEMBER 30, 2025 and 2024

Overview

White Mountains reported book value per share of $1,851 as of September 30, 2025, an increase of 3% for the third quarter of 2025 and 6% for the first nine months of 2025, including dividends. Results in the third quarter and first nine months of 2025 were driven primarily by good operating results and investment returns.

White Mountains reported book value per share of $1,795 as of September 30, 2024, an increase of 4% in the third quarter of 2024 and 9% in the first nine months of 2024, including dividends. Results in the third quarter and first nine months of 2024 were driven primarily by mark-to-market gains from the increase in MediaAlpha’s share price as well as solid operating results and good investment returns.

Comprehensive income (loss) attributable to common shareholders was $114 million and $272 million in the third quarter and first nine months of 2025 compared to $180 million and $361 million in the third quarter and first nine months of 2024. Results in the third quarter and first nine months of 2025 included $8 million and $2 million of unrealized investment gains from White Mountains’s investment in MediaAlpha compared to $88 million and $160 million of net realized and unrealized investment gains in the third quarter and first nine months of 2024.

On October 2, 2025, White Mountains entered into the Bamboo Sale Transaction to sell approximately 77% of its equity interest in Bamboo for cash and retain the remainder. The Bamboo Sale Transaction values Bamboo at an enterprise value of $1.75 billion. White Mountains expects to receive net cash proceeds of approximately $840 million and will retain a $250 million interest in Bamboo, representing approximately 15% on a fully-diluted/fully-converted basis. Including the estimated fourth quarter impact from the closing of the Bamboo Sale Transaction of approximately $325 per share, White Mountains’s book value per share would be $2,176 as of September 30, 2025. The estimated per share impact increased from the $310 previously reported to $325, driven primarily by expected distributions from Bamboo and certain compensation and other costs recorded in connection with the transaction in White Mountains’s third quarter financial statements. The Bamboo Group’s assets and liabilities have been presented as held for sale within Other Operations in White Mountains’s third quarter financial statements. The Bamboo Sale Transaction is expected to close in the fourth quarter of 2025.

On September 2, 2025, White Mountains closed its transaction to acquire a controlling financial interest in Distinguished, a full-service MGA and program administrator for specialty property & casualty insurance.

On July 18, 2025, White Mountains closed its transaction to deploy $150 million into BroadStreet through the BroadStreet SPV alongside co-lead investors Ethos Capital LP and British Columbia Investment Management Corporation. BroadStreet is an insurance brokerage company with a presence in all 50 U.S. states and ten Canadian provinces.

Including the expected proceeds from the Bamboo Sale Transaction, undeployed capital will be roughly $1.1 billion.

The Ark/WM Outrigger segment’s combined ratio was 73% and 83% in the third quarter and first nine months of 2025 compared to 77% and 84% in the third quarter and first nine months of 2024. The Ark/WM Outrigger segment reported gross written premiums of $366 million and $2,289 million, net written premiums of $287 million and $1,593 million and net earned premiums of $542 million and $1,264 million in the third quarter and first nine months of 2025 compared to gross written premiums of $374 million and $1,943 million, net written premiums of $339 million and $1,440 million and net earned premiums of $552 million and $1,173 million in the third quarter and first nine months of 2024. The Ark/WM Outrigger segment reported pre-tax income of $126 million and $270 million in the third quarter and first nine months of 2025 compared to $141 million and $242 million in the third quarter and first nine months of 2024.

Ark’s combined ratio was 76% and 84% in the third quarter and first nine months of 2025 and compared to 79% and 85% third quarter and first nine months of 2024. Ark’s combined ratio in the third quarter of 2025 included minimal catastrophe losses. Ark’s combined ratio in the first nine months of 2025 included seven points of catastrophe losses, driven primarily by losses related to the January 2025 California wildfires. This compares to 17 points and eight points of catastrophe losses in the third quarter and first nine months of 2024, driven primarily by Hurricanes Helene, Debby and Beryl as well as Calgary hailstorms. Non-catastrophe losses in the third quarter and first nine months of 2025 included $30 million on a net basis related to a refinery fire in California. Ark’s combined ratio included zero points and five points of net favorable prior year development in the third quarter and first nine months of 2025, driven by the property and specialty lines of business. This included four points of unfavorable development in the first nine months of 2025 related to aviation losses from the conflict in Ukraine and Russia. This compares to five points and three points of net favorable prior year development in the third quarter and first nine months of 2024, driven primarily by the property line of business.

Ark reported gross written premiums of $366 million and $2,289 million, net written premiums of $283 million and $1,510 million and net earned premiums of $499 million and $1,202 million in the third quarter and first nine months of 2025 compared to gross written premiums of $374 million and $1,943 million, net written premiums of $331 million and $1,358 million and net earned premiums of $507 million and $1,111 million in the third quarter and first nine months of 2024. Premium growth in the first nine months of 2025 was driven primarily by the addition of new underwriting teams and classes of business in the property and specialty lines of business. Ark reported pre-tax income of $97 million and $240 million in the third quarter and first nine months of 2025 compared to $119 million and $202 million in the third quarter and first nine months of 2024. Ark’s results included net realized and unrealized investment gains of $18 million and $99 million in the third quarter and first nine months of 2025 compared to $53 million and $84 million in the third quarter and first nine months of 2024.

WM Outrigger Re’s combined ratio was 38% and 63% in the third quarter and first nine months of 2025 compared to 58% and 50% in the third quarter and first nine months of 2024. Catastrophe losses in the first nine months of 2025 included $19 million of losses related to the California wildfires, net of reinstatement premiums.

WM Outrigger Re reported gross written premiums of $4 million and $84 million and net earned premiums of $44 million and $63 million in the third quarter and first nine months of 2025 compared to gross written premiums of $9 million and $82 million and net earned premiums of $45 million and $63 million in the third quarter and first nine months of 2024. WM Outrigger Re reported pre-tax income of $29 million and $30 million in the third quarter and first nine months of 2025 compared to $22 million and $40 million in the third quarter and first nine months of 2024. Through September 30, 2025, WM Outrigger Re has generated pre-tax income of $40 million from the 2025 underwriting year, $28 million from the 2024 underwriting year and $76 million from the 2023 underwriting year. White Mountains’s capital commitment to WM Outrigger Re was $150 million for the 2025 underwriting year, $130 million for the 2024 underwriting year and $205 million for the 2023 underwriting year.

HG Global reported gross written premiums of $16 million and $42 million and earned premiums of $8 million and $23 million in the third quarter and first nine months of 2025 compared to gross written premiums of $14 million and $35 million and earned premiums of $8 million and $22 million in the third quarter and first nine months of 2024. HG Global’s total par value of policies assumed was $850 million and $2,208 million in the third quarter and first nine months of 2025 compared to $688 million and $2,012 million in the third quarter and first nine months of 2024. HG Global’s total gross pricing was 187 and 189 basis points in the third quarter and first nine months of 2025 compared to 203 and 171 basis points in the third quarter and first nine months of 2024. HG Global reported pre-tax income (loss) of $22 million and $64 million in the third quarter and first nine months of 2025 compared to $(63) million and $(46) million in the third quarter and first nine months of 2024. HG Global’s results included net realized and unrealized investment gains of $7 million and $20 million in the third quarter and first nine months of 2025 compared to $23 million and $13 million in the third quarter and first nine months of 2024, driven by a decrease in interest rates. HG Global’s results in the third quarter and first nine months of 2024 also included the loss on deconsolidation of $115 million, partially offset by an increase in fair value of the BAM surplus notes of $16 million during the third quarter of 2024. The fair value of the BAM Surplus Notes was $396 million as of September 30, 2025 compared to $397 million as of June 30, 2025. The decline was driven by $8 million of principal and interest payments, largely offset by approximately $8 million of accrued interest.

Kudu reported total revenues of $54 million and $139 million, pre-tax income of $44 million and $108 million and adjusted EBITDA of $15 million and $47 million in the third quarter and first nine months of 2025 compared to total revenues of $47 million and $128 million, pre-tax income of $38 million and $101 million and adjusted EBITDA of $14 million and $41 million in the third quarter and first nine months of 2024. Total revenues, pre-tax income and adjusted EBITDA included $18 million and $57 million of net investment income in the third quarter and first nine months of 2025 compared to $17 million and $50 million in the third quarter and first nine months of 2024. Total revenues and pre-tax income also included $36 million and $81 million of net realized and unrealized investment gains in the third quarter and first nine months of 2025 compared to $30 million and $78 million in the third quarter and first nine months of 2024.

Kudu deployed $120 million, including transaction costs, into two new asset management firms in 2025. As of September 30, 2025, Kudu has deployed $1.1 billion, including transaction costs, into 29 asset and wealth management firms globally, including three that have been exited. As of September 30, 2025, the asset and wealth management firms have combined assets under management (“AUM”) of approximately $146 billion, spanning a range of asset classes.

Bamboo reported commission and fee revenues of $64 million and $167 million and pre-tax income of $15 million and $37 million in the third quarter and first nine months of 2025 compared to commission and fee revenues of $43 million and $97 million and pre-tax income of $16 million and $23 million in the third quarter and first nine months of 2024. Bamboo reported MGA pre-tax income of $15 million and $40 million and MGA adjusted EBITDA of $28 million and $74 million in the third quarter and first nine months of 2025 compared to MGA pre-tax income of $14 million and $21 million and MGA adjusted EBITDA of $19 million and $37 million in the third quarter and first nine months of 2024. Managed premiums, which represent the total premiums placed by Bamboo, were $221 million and $558 million in the third quarter and first nine months of 2025 compared to $148 million and $358 million in the third quarter and first nine months of 2024. The increase in managed premiums was driven by growth in the renewal book as well as new business volume.

For the period from September 2, 2025, the date of acquisition, through September 30, 2025, Distinguished reported managed premiums of $43 million, commission and fee revenues of $14 million, pre-tax loss of $3 million and ScaleCo adjusted EBITDA of $1 million.

As of September 30, 2025, White Mountains owned 17.9 million shares of MediaAlpha, representing a 27% basic ownership interest (25% on a fully-diluted/fully-converted basis). As of September 30, 2025, MediaAlpha’s share price was $11.38 per share, which increased from $10.95 per share as of June 30, 2025. The carrying value of White Mountains’s investment in MediaAlpha was $203 million as of September 30, 2025 compared to $196 million at June 30, 2025. At White Mountains’s current level of ownership, each $1.00 per share increase or decrease in the share price of MediaAlpha will result in an approximate $7.00 per share increase or decrease in White Mountains’s book value per share.

White Mountains’s total consolidated portfolio return on invested assets was 2.1% in the third quarter of 2025, which included $8 million of unrealized investment gains from White Mountains’s investment in MediaAlpha. Excluding MediaAlpha, the total consolidated portfolio return on invested assets was 2.0% in the third quarter of 2025, driven primarily by net investment income and net unrealized investment gains from the other long-term investments and fixed income portfolios. White Mountains’s total consolidated portfolio return on invested assets was 4.6% in the third quarter of 2024, which included $88 million of unrealized investment gains from White Mountains’s investment in MediaAlpha. Excluding MediaAlpha, the total consolidated portfolio return on invested assets was 3.3% in the third quarter of 2024, driven primarily by net investment income and net unrealized investment gains from the fixed income and other long-term investments portfolios.

White Mountains’s total consolidated portfolio return on invested assets was 6.6% in the first nine months of 2025, which included $2 million of unrealized investment gains from White Mountains’s investment in MediaAlpha. Excluding MediaAlpha, the total consolidated portfolio return on invested assets was 6.8% in the first nine months of 2025, driven primarily by net investment income and net unrealized investment gains from the other long-term investments and fixed income portfolios. White Mountains’s total consolidated portfolio return on invested assets was 9.4% in the first nine months of 2024, which included $160 million of net realized and unrealized investment gains from White Mountains’s investment in MediaAlpha. Excluding MediaAlpha, the total consolidated portfolio return on invested assets was 6.9% in the first nine months of 2024, driven primarily by net investment income and net unrealized investment gains from the fixed income, common equity securities and other-long term investments portfolios.

Book Value Per Share

The following table presents White Mountains’s book value per share as of September 30, 2025, June 30, 2025, December 31, 2024 and September 30, 2024:

Goodwill and Other Intangible Assets

The following table presents goodwill and other intangible assets that are included in White Mountains’s book value as of September 30, 2025, June 30, 2025, December 31, 2024 and September 30, 2024:

(1) The relative fair values of goodwill and other intangible assets recognized in connection with the Distinguished Transaction and the Enterprise Solutions Transaction had not yet been finalized. All amounts related to the Distinguished Transaction were reflected as goodwill as of September 30, 2025. See Note 2 — “Significant Transactions.” on page 12.

(2) See Note 4 — “Goodwill and Other Intangible Assets” on page 27 for details of other intangible assets.

(3) Amounts reflect the basic ownership percentage of the noncontrolling shareholders.

Summary of Consolidated Results

The following table presents White Mountains’s consolidated financial results by industry for the three and nine months ended September 30, 2025 and 2024:

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I. SUMMARY OF OPERATIONS BY SEGMENT

As of September 30, 2025, White Mountains conducted its operations through five reportable segments: (1) Ark/WM Outrigger, (2) HG Global, (3) Kudu, (4) Bamboo and (5) Distinguished, 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 CODMs and its Board of Directors. Significant intercompany transactions among White Mountains’s segments have been eliminated herein. White Mountains’s segment information is presented in Note 14 — “Segment Information” to the Consolidated Financial Statements.

Effective September 30, 2025, as a result of the Bamboo Sale Transaction, the Bamboo Group’s assets and liabilities have been presented as held for sale in White Mountains’s consolidated balance sheets. See Note 2 - “Significant Transactions.”

Effective July 1, 2024, White Mountains no longer consolidates BAM. Through June 30, 2024, BAM’s results of operations were presented within the HG Global segment. See Note 2 - “Significant Transactions.”

A discussion of White Mountains’s consolidated investment operations is included after the discussion of operations by segment.

Ark/WM Outrigger

Ark is a specialty property and casualty insurance and reinsurance company that offers a wide range of niche insurance and reinsurance products, including property, specialty, marine & energy, casualty and accident & health. Ark underwrites select coverages through its two major subsidiaries in the United Kingdom and Bermuda.

Ark sponsored the formation of Outrigger Re Ltd., a Bermuda company registered as a special purpose insurer and segregated accounts company, to provide collateralized reinsurance protection on Ark’s Bermuda global property catastrophe excess of loss portfolio. White Mountains consolidates its segregated account of Outrigger Re Ltd., WM Outrigger Re, in its financial statements.

The following tables present the components of pre-tax income (loss) included in the Ark/WM Outrigger segment for the three and nine months ended September 30, 2025 and 2024:

63

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Ark/WM Outrigger Results—Three Months Ended September 30, 2025 versus Three Months Ended September 30, 2024

The Ark/WM Outrigger segment’s combined ratio was 73% and 77% in the third quarter of 2025 and 2024. The Ark/WM Outrigger segment reported gross written premiums of $366 million, net written premiums of $287 million and net earned premiums of $542 million in the third quarter of 2025 compared to gross written premiums of $374 million, net written premiums of $339 million and net earned premiums of $552 million in the third quarter of 2024. The Ark/WM Outrigger segment reported pre-tax income of $126 million in the third quarter of 2025 compared to $141 million in the third quarter of 2024.

Ark’s combined ratio was 76% and 79% in the third quarter of 2025 and 2024. Catastrophe losses were minimal in the third quarter of 2025 compared to seventeen points in the third quarter of 2024, driven primarily by Hurricanes Helene, Debby and Beryl as well as Calgary hailstorms. Non-catastrophe losses in the third quarter of 2025 included $30 million on a net basis related to a refinery fire in California. Ark’s combined ratio in the third quarter of 2025 included zero points of net favorable prior year loss reserve development, driven primarily by four points of net favorable development in the property and specialty lines of business, offset by four points of unfavorable development related to aviation losses from the conflict in Ukraine and Russia. This compares to five points of net favorable prior year loss reserve development in the third quarter of 2024, driven primarily by the property line of business.

Ark reported gross written premiums of $366 million, net written premiums of $283 million and net earned premiums of $499 million in the third quarter of 2025 compared to gross written premiums of $374 million, net written premiums of $331 million and net earned premiums of $507 million in the third quarter of 2024. The decrease in gross written premiums was driven primarily by non-recurring reinstatement premiums related to prior year catastrophes and the timing of a structured property reinsurance program that incepted in the third quarter of 2024 and renewed in the second quarter of 2025, which collectively impacted prior year gross written premiums by roughly $40 million, partially offset by growth in the specialty and marine & energy lines of business. Ark reported pre-tax income of $97 million in the third quarter of 2025 compared to $119 million in the third quarter of 2024. Ark’s results included net realized and unrealized investment gains of $18 million in the third quarter of 2025, driven primarily by net realized and unrealized investment gains from common equity securities and fixed maturity investments, compared to net realized and unrealized investment gains of $53 million in the third quarter of 2024, driven primarily by net unrealized investment gains from fixed maturity securities due to the decrease in interest rates. Ark’s results also included a $36 million expense related to the increase in fair value of White Mountains’s contingent consideration liability in the third quarter of 2025 compared to $34 million in the third quarter of 2024.

WM Outrigger Re’s combined ratio was 38% in the third quarter of 2025 compared to 58% in the third quarter of 2024. Catastrophe losses were minimal in the third quarter of 2025. Catastrophe losses in third quarter of 2024 included Hurricanes Helene, Debby and Beryl as well as Calgary hailstorms. In the third quarter of 2025, WM Outrigger Re’s combined ratio was 40% for the 2025 underwriting year and 99% for the 2024 underwriting year. In the third quarter of 2024, WM Outrigger Re’s combined ratio was 58% for the 2024 underwriting year and 61% for the 2023 underwriting year.

WM Outrigger Re reported gross written premiums of $4 million and net earned premiums of $44 million in the third quarter of 2025 compared to gross written premiums of $9 million and net earned premiums of $45 million in the third quarter of 2024. WM Outrigger Re reported pre-tax income of $29 million, all of which was attributable to the 2025 underwriting year. WM Outrigger Re reported pre-tax income of $22 million in the third quarter of 2024, substantially all of which was attributable to the 2024 underwriting year.

The following tables present the Ark/WM Outrigger segment’s insurance premiums, insurance expenses and insurance ratios for the three months ended September 30, 2025 and 2024:

$ in Millions

(1) Included within general and administrative expenses in the consolidated statement of operations.

$ in Millions

(1) Included within general and administrative expenses in the consolidated statement of operations.

The following table presents WM Outrigger Re’s insurance premiums, combined ratio and pre-tax income by underwriting year for the three months ended September 30, 2025 and 2024:

$ in Millions

Gross Written Premiums

Gross written premiums decreased 2% to $366 million in the third quarter of 2025 compared to $374 million in the third quarter of 2024, with risk adjusted rate change of -4%. The decrease in gross written premiums was driven primarily by non-recurring reinstatement premiums related to prior year catastrophes and the timing of a structured property reinsurance program that incepted in the third quarter of 2024 and renewed in the second quarter of 2025, partially offset by growth in the specialty and marine & energy lines of business.

The following table presents the Ark/WM Outrigger segment’s gross written premiums by line of business for the three months ended September 30, 2025 and 2024:

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Ark/WM Outrigger Results—Nine Months Ended September 30, 2025 versus Nine Months Ended September 30, 2024

The Ark/WM Outrigger segment’s combined ratio was 83% in the first nine months of 2025 compared to 84% in the first nine months of 2024. The Ark/WM Outrigger segment reported gross written premiums of $2,289 million, net written premiums of $1,593 million and net earned premiums of $1,264 million in the first nine months of 2025 compared to gross written premiums of $1,943 million, net written premiums of $1,440 million and net earned premiums of $1,173 million in the first nine months of 2024. The Ark/WM Outrigger segment reported pre-tax income of $270 million in the first nine months of 2025 compared to $242 million in the first nine months of 2024.

Ark’s combined ratio was 84% in the first nine months of 2025 compared to 85% in the first nine months of 2024. Ark’s combined ratio in the first nine months of 2025 included seven points of catastrophe losses, driven by losses related to the January 2025 California wildfires of $75 million on a net basis after reinsurance and reinstatement premiums, compared to eight points of catastrophe losses in the first nine months of 2024, driven primarily by Hurricanes Helene, Debby and Beryl as well as Calgary hailstorms. Non-catastrophe losses in the first nine months of 2025 included $30 million on a net basis related to a refinery fire in California. Ark’s combined ratio in the first nine months of 2025 included five points of net favorable prior year loss reserve development, driven primarily by nine points of net favorable development in the property and specialty lines of business, partially offset by four points of unfavorable development related to aviation losses from the conflict in Ukraine and Russia. This compares to three points of net favorable prior year loss reserve development in the first nine months of 2024, driven primarily by the property line of business.

Ark reported gross written premiums of $2,289 million, net written premiums of $1,510 million and net earned premiums of $1,202 million in the first nine months of 2025 compared to gross written premiums of $1,943 million, net written premiums of $1,358 million and net earned premiums of $1,111 million in the first nine months of 2024. The increase in gross written premiums was driven primarily by the addition of new underwriting teams and classes of business in the property and specialty lines of business.

Ark reported pre-tax income of $240 million in the first nine months of 2025 compared to $202 million in the first nine months of 2024. Ark’s results included net realized and unrealized investment gains of $99 million in the first nine months of 2025, driven primarily by net unrealized investment gains from other long-term investments, common equity securities and foreign currency, compared to $84 million in the first nine months of 2024, driven primarily by net unrealized investment gains from common equity securities and net unrealized investment gains from fixed maturity securities due to the decrease in interest rates. Ark’s results for the first nine months of 2025 also included a $74 million expense related to the increase in fair value of White Mountains’s contingent consideration liability compared to $48 million in the first nine months of 2024.

WM Outrigger Re’s combined ratio was 63% in the first nine months of 2025 compared to 50% in the first nine months of 2024. Catastrophe losses in the first nine months of 2025 included $19 million of losses related to the California wildfires, net of reinstatement premiums. Catastrophe losses in 2024 included Hurricanes Helene, Debby and Beryl as well as Calgary hailstorms. WM Outrigger Re’s losses related to the California wildfires were $2 million for the 2025 underwriting year and $17 million for the 2024 underwriting year. In the first nine months of 2025, WM Outrigger Re’s combined ratio was 42% for the 2025 underwriting year and 279% for the 2024 underwriting year. In the first nine months of 2024, WM Outrigger Re’s combined ratio was 52% for the 2024 underwriting year and 30% for the 2023 underwriting year.

WM Outrigger Re reported gross written premiums of $84 million and net earned premiums of $63 million in the first nine months of 2025 compared to gross written premiums of $82 million and net earned premiums of $63 million in the first nine months of 2024. WM Outrigger Re reported pre-tax income of $30 million in the first nine months of 2025, of which $40 million related to the 2025 underwriting year and $(10) million related to the 2024 underwriting year. WM Outrigger Re reported pre-tax income of $40 million in the first nine months of 2024, of which $36 million related to the 2024 underwriting year and $4 million related to the 2023 underwriting year.

The following tables present the Ark/WM Outrigger segment’s insurance premiums, insurance expenses and insurance ratios for the nine months ended September 30, 2025 and 2024:

$ in Millions

(1) Included within general and administrative expenses in the consolidated statement of operations.

$ in Millions

(1) Included within general and administrative expenses in the consolidated statement of operations.

The following table presents WM Outrigger Re’s insurance premiums, combined ratio and pre-tax income by underwriting year for the nine months ended September 30, 2025 and 2024:

$ in Millions

Through September 30, 2025, WM Outrigger Re has generated pre-tax income of $40 million from the 2025 underwriting year, $28 million from the 2024 underwriting year and $76 million from the 2023 underwriting year. White Mountains’s capital commitment to WM Outrigger Re was $150 million for the 2025 underwriting year, $130 million for the 2024 underwriting year and $205 million for the 2023 underwriting year.

Gross Written Premiums

Gross written premiums increased 18% to $2,289 million in the first nine months of 2025 compared to $1,943 million in the first nine months of 2024, with risk adjusted rate change of -3%. The increase in gross written premiums was driven primarily by the addition of new underwriting teams and classes of business in the property and specialty lines of business. The risk adjusted rate change on the Outrigger Re Ltd. portfolio of global property reinsurance in the first nine months of 2025 was -5% year-over-year.

The following table presents the Ark/WM Outrigger segment’s gross written premiums by line of business for the nine months ended September 30, 2025 and 2024:

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Ark/WM Outrigger Balance Sheets

The following tables present amounts from Ark and WM Outrigger Re that are contained within White Mountains’s consolidated balance sheets as of September 30, 2025 and December 31, 2024:

(1) Amount is net of $43.9 of deferred tax liabilities related to the other intangible assets.

(2) See “NON-GAAP FINANCIAL MEASURES” on page 92.

(1) Amount is net of $43.9 of deferred tax liabilities related to the other intangible assets.

(2) See “NON-GAAP FINANCIAL MEASURES” on page 92.

HG Global

HG Global was established to fund the startup of BAM and, through its reinsurance subsidiary HG Re, to provide up to 15%-of-par, first-loss reinsurance protection for policies underwritten by BAM.

The following table presents the components of pre-tax income (loss) included in the HG Global segment for the three and nine months ended September 30, 2025 and 2024. The HG Global segment consists of HG Global, which includes HG Re and its other wholly-owned subsidiaries, and, prior to its deconsolidation on July 1, 2024, BAM. Through June 30, 2024, BAM’s results of operations were presented within the HG Global segment. See Note 2 — “Significant Transactions.”

(1) Upon the deconsolidation of BAM, the BAM Surplus Notes, including accrued interest receivable, were fair valued in accordance with GAAP at $387 million, which resulted in an unrealized loss on deconsolidation of $115 million.

(2) For the three months ended September 30, 2024, the amount includes $0.3 of intercompany interest expense that is eliminated in White Mountains’s consolidated financial statements. For segment reporting, HG Global’s intercompany interest expense included within the HG Global segment is eliminated against the offsetting intercompany interest income included within Other Operations.

(1) Effective July 1, 2024, White Mountains no longer consolidates BAM. For the period from January 1, 2024 through June 30, 2024, BAM’s results of operations were presented within the HG Global segment.

(2) Upon the deconsolidation of BAM, the BAM Surplus Notes, including accrued interest receivable, were fair valued in accordance with GAAP at $387 million, which resulted in an unrealized loss on deconsolidation of $115 million.

(3) For the nine months ended September 30, 2024, the amount includes $(0.3) of intercompany general and administrative expenses that are eliminated in White Mountains’s consolidated financial statements. For segment reporting, HG Global’s intercompany general and administrative expenses included within the HG Global segment are eliminated against the offsetting intercompany general and administrative expenses included within Other Operations.

(4) For the nine months ended September 30, 2024, the amount includes $0.8 of intercompany interest expense that is eliminated in White Mountains’s consolidated financial statements. For segment reporting, HG Global’s intercompany interest expense included within the HG Global segment is eliminated against the offsetting intercompany interest income included within Other Operations.

HG Global Results—Three Months Ended September 30, 2025 versus Three Months Ended September 30, 2024

HG Global reported gross written premiums of $16 million and earned premiums of $8 million in the third quarter of 2025 compared to gross written premiums of $14 million and earned premiums of $8 million in the third quarter of 2024. HG Global reported gross written premiums net of ceding commission paid of $11 million in the third quarter of 2025 compared to $10 million in the third quarter of 2024. HG Global’s total par value of policies assumed, which represents its first-loss exposure on policies assumed from BAM, was $850 million in the third quarter of 2025, of which $693 million was in the primary market and $158 million was in the secondary market. This compares to $688 million in the third quarter of 2024, of which $582 million was in the primary market and $106 million was in the secondary market. The increase in primary market par assumed was driven by increased municipal bond issuance. The increase in secondary market par assumed was driven by continued uncertainty in the municipal bond market, which created more demand for bond insurance.

HG Global’s total gross pricing was 187 basis points in the third quarter of 2025, compared to 203 basis points in the third quarter of 2024. Pricing in the primary market decreased to 128 basis points in the third quarter of 2025 compared to 168 basis points in the third quarter of 2024, due to a lower proportion of large, high-priced issuances insured by BAM in the third quarter of 2025. Pricing in the secondary market, which is more transaction specific than pricing in the primary market, increased to 444 basis points in the third quarter of 2025 compared to 396 basis points in the third quarter of 2024. Total pricing net of ceding commission paid decreased to 131 basis points in the third quarter of 2025 compared to 144 basis points in the third quarter of 2024.

The following table presents HG Global’s par value assumed, reinsurance premiums and pricing for the three months ended September 30, 2025 and 2024:

$ in Millions

(1) For capital appreciation bonds, par is adjusted to the estimated equivalent par value for current interest paying bonds.

HG Global reported pre-tax income (loss) of $22 million in the third quarter of 2025 compared to $(63) million in the third quarter of 2024. HG Global’s results in the third quarter of 2025 included net realized and unrealized investment gains on its fixed income portfolio of $7 million compared to $23 million in the third quarter of 2024, driven by a decrease in interest rates in each period. HG Global’s results included interest income on the BAM Surplus Notes of $8 million in both the third quarter of 2025 and 2024. HG Global’s results in the third quarter of 2024 also included the loss on deconsolidation of BAM of $115 million, partially offset by an increase in fair value of the BAM surplus notes of $16 million during the quarter.

The fair value of the BAM Surplus Notes decreased to $396 million as of September 30, 2025 compared to $397 million as of June 30, 2025, resulting from an $8 million cash payment of principal and interest, largely offset by approximately $8 million of accrued interest. Of this payment, $6 million was a repayment of principal held in the Supplemental Trust, less than $1 million was a payment of accrued interest held in the Supplemental Trust and $2 million was a payment of accrued interest held outside the Supplemental Trust. During the third quarter of 2024, HG Global did not receive any payments of principal and interest on the BAM Surplus Notes.

During the third quarter of 2025, HG Re received a distribution from the Supplemental Trust of $15 million, which consisted of an assignment of accrued interest on the BAM Surplus Notes of $7 million and a cash distribution of $8 million. During the third quarter of 2024, HG Re received a distribution from the Supplemental Trust of $12 million, which consisted of an assignment of accrued interest on the BAM Surplus Notes.

HG Global Results—Nine Months Ended September 30, 2025 versus Nine Months Ended September 30, 2024

HG Global reported gross written premiums of $42 million and earned premiums of $23 million in the first nine months of 2025 compared to gross written premiums of $35 million and earned premiums of $22 million in the first nine months of 2024. HG Global reported gross written premiums net of ceding commission paid of $29 million in the first nine months of 2025 compared to $24 million in the first nine months of 2024. HG Global’s total par value of policies assumed was $2,208 million in the first nine months of 2025, of which $1,860 million was in the primary market and $348 million was in the secondary market. This compares to $2,012 million in the first nine months of 2024, of which $1,760 million was in the primary market and $252 million was in the secondary market. The increase in primary market par assumed was driven by increased municipal bond issuance. The increase in secondary market par assumed was driven by increased volatility and uncertainty in the municipal bond market, which created more demand for bond insurance.

HG Global’s total gross pricing was 189 basis points in the first nine months of 2025 compared to 171 basis points in the first nine months of 2024. Pricing in the primary market increased to 158 basis points in the first nine months of 2025 compared to 133 basis points in the first nine months of 2024, due to a greater proportion of large, high-priced issuances insured by BAM in the first nine months of 2025. Pricing in the secondary market, which is more transaction specific than pricing in the primary market, decreased to 356 basis points in the first nine months of 2025 compared to 437 basis points in the first nine months of 2024. Total pricing net of ceding commission paid increased to 133 basis points in the first nine months of 2025 compared to 121 basis points in the first nine months of 2024.

The following table presents HG Global’s par value assumed, reinsurance premiums and pricing for the nine months ended September 30, 2025 and 2024:

$ in Millions

(1) For capital appreciation bonds, par is adjusted to the estimated equivalent par value for current interest paying bonds.

HG Global reported pre-tax income (loss) of $64 million in the first nine months of 2025 compared to $(47) million in the first nine months of 2024. HG Global’s results in the first nine months of 2025 included net realized and unrealized investment gains on its fixed income portfolio of $20 million compared to $13 million in the first nine months of 2024, driven by a decrease in interest rates in each period. HG Global’s results in the first nine months of 2025 included interest income on the BAM Surplus Notes of $23 million compared to $21 million in the first nine months of 2024. HG Global’s results in the first nine months of 2024 also included the loss on the deconsolidation of BAM of $115 million, partially offset by an increase in fair value of the BAM surplus notes of $16 million.

The fair value of the BAM Surplus Notes increased to $396 million as of September 30, 2025 compared to $382 million as of December 31, 2024, resulting from $23 million of accrued interest, partially offset by an $8 million cash payment of principal and interest. Of this payment, $6 million was a repayment of principal held in the Supplemental Trust, less than $1 million was a payment of accrued interest held in the Supplemental Trust and $2 million was a payment of accrued interest held outside the Supplemental Trust. During the first nine months of 2024, HG Global received cash payments of principal and interest on the BAM Surplus Notes totaling $8 million. Of this payment, $5 million was a repayment of principal held in the Supplemental Trust, less than $1 million was a payment of accrued interest held in the Supplemental Trust and $3 million was a payment of accrued interest held outside the Supplemental Trust.

During the first nine months of 2025, HG Re received a distribution from the Supplemental Trust of $38 million, which consisted of an assignment of accrued interest on the BAM Surplus Notes of $23 million and a cash distribution of $15 million. During the first nine months of 2024, HG Re received a distribution from the Supplemental Trust of $44 million, which consisted of an assignment of accrued interest on the BAM Surplus Notes.

HG Global Balance Sheets

The following table presents amounts for the HG Global segment that are presented within White Mountains’s consolidated balance sheets as of September 30, 2025 and December 31, 2024.

(1) The fair value of the BAM Surplus Notes includes accrued interest receivable.

(2) HG Global’s preferred dividends payable to White Mountains are eliminated in White Mountains’s consolidated financial statements. For segment reporting, these amounts are included within the HG Global segment and are eliminated against the offsetting receivables included within Other Operations.

HG Global Unearned Premiums, Net of Deferred Acquisition Costs

The following table presents HG Global’s unearned premiums, net of deferred acquisition costs:

77

Kudu

Kudu provides capital solutions for boutique asset and wealth managers for a variety of purposes including generational ownership transfers, management buyouts, acquisition and growth finance and legacy partner liquidity. Kudu also provides strategic advice to managers from time to time.

Kudu deployed $120 million, including transaction costs, into two new asset management firms in 2025. As of September 30, 2025, Kudu has deployed a total of $1.1 billion, including transaction costs, into 29 asset and wealth management firms globally, including three that have been exited. As of September 30, 2025, the asset and wealth management firms have combined AUM of approximately $146 billion, spanning a range of asset classes, including real estate, real assets, wealth management, hedge funds, private equity and alternative credit strategies. Kudu’s capital was deployed at an average gross cash yield at inception of approximately 9.4% based on expected cash flows in the first year following deployment.

The following table presents the components of GAAP net income (loss), EBITDA and adjusted EBITDA included in the Kudu segment for the three and nine months ended September 30, 2025 and 2024:

(1) Net investment income includes revenues from Participation Contracts and income from short-term and other long-term investments.

(2) See “NON-GAAP FINANCIAL MEASURES” on page 92.

The following table presents the changes to the fair value of Kudu’s Participation Contracts:

(1) As of June 30, 2025, June 30, 2024, December 31, 2024 and December 31, 2023, Kudu’s other long-term investments also include $6.1, $5.8, $5.6 and $5.8 related to a private debt instrument.

(2) Includes $28.1 of proceeds receivable from Participation Contracts sold during the three and nine months ended September 30, 2024.

(3) Includes net realized and unrealized investment gains (losses) recognized from Participation Contracts beginning in the quarter a contract is classified as pending sale.

(4) Includes net unrealized investment gains (losses) recognized from (i) ongoing Participation Contracts and (ii) Participation Contracts prior to classification as pending sale.

(5) As of both September 30, 2025 and 2024, Kudu’s other long-term investments also include $6.2 related to a private debt instrument.

Kudu Results—Three Months Ended September 30, 2025 versus Three Months Ended September 30, 2024

Kudu reported total revenues of $54 million, pre-tax income of $44 million and adjusted EBITDA of $15 million in the third quarter of 2025 compared to total revenues of $47 million, pre-tax income of $38 million and adjusted EBITDA of $14 million in the third quarter of 2024. Total revenues, pre-tax income and adjusted EBITDA included $18 million of net investment income in the third quarter of 2025 compared to $17 million in the third quarter of 2024. The increase in net investment income was primarily due to amounts earned from new investments made subsequent to September 30, 2024. This was partially offset by a decrease in dividends from certain participation contracts. Total revenues and pre-tax income also included $36 million of net realized and unrealized investment gains in the third quarter of 2025 compared to $30 million in the third quarter of 2024. Net realized and unrealized investment gains in the third quarter of 2025 were driven by an increase in the fair value of Kudu’s Participation Contracts, driven primarily by lower discount rates across the portfolio and growth in AUM at several managers. Net realized and unrealized investment gains in the third quarter of 2024 were driven by an increase in the fair value of Kudu’s Participation Contracts, driven primarily by lower discount rates across the portfolio.

Kudu Results—Nine Months Ended September 30, 2025 versus Nine Months Ended September 30, 2024

Kudu reported total revenues of $139 million, pre-tax income of $108 million and adjusted EBITDA of $47 million in the first nine months of 2025 compared to total revenues of $128 million, pre-tax income of $101 million and adjusted EBITDA of $41 million in the first nine months of 2024. Total revenues, pre-tax income and adjusted EBITDA included $57 million of net investment income in the first nine months of 2025 compared to $50 million in the first nine months of 2024. The increase in net investment income was driven primarily by amounts earned from new deployments that Kudu made subsequent to September 30, 2024. Total revenues and pre-tax income also included $81 million of net realized and unrealized investment gains in the first nine months of 2025 compared to $78 million in the first nine months of 2024. Net realized and unrealized investment gains in the first nine months of 2025 were driven by an increase in the fair value of Kudu’s Participation Contracts, primarily due to growth in AUM at several managers and foreign currency gains resulting from the weakening of the U.S. dollar. Net realized and unrealized investment gains for the first nine months of 2024 were driven by an increase in the fair value of Kudu’s Participation Contracts, primarily due to lower discount rates and growth in AUM at several managers, partially offset by a decline in the share price from a publicly listed security received by Kudu in a prior sales transaction.

Bamboo

On January 2, 2024, White Mountains acquired a controlling interest in Bamboo. Bamboo is a capital-light, tech- and data-enabled insurance distribution platform providing homeowners’ insurance and related products to the residential property market in California. Bamboo operates primarily through Bamboo MGA, its full-service MGA business, where the company manages all aspects of the placement process on behalf of its Capacity Providers, including product development, marketing, underwriting, policy issuance and claims oversight, and it earns commissions based on the volume and profitability of the insurance that it places.

On October 2, 2025, White Mountains entered into the Bamboo Sale Transaction to sell approximately 77% of its equity interest in Bamboo for cash and retain the remainder. The Bamboo Sale Transaction values Bamboo at an enterprise value of $1.75 billion. White Mountains expects to receive net cash proceeds of approximately $840 million and will retain a $250 million interest in Bamboo, representing approximately 15% on a fully-diluted/fully-converted basis. The Bamboo Sale Transaction is expected to close in the fourth quarter of 2025. See Note 2 — “Significant Transactions.”

The following table presents the components of GAAP net income (loss), MGA net income (loss), MGA EBITDA and MGA adjusted EBITDA included in White Mountains’s Bamboo segment for the three and nine months ended September 30, 2025 and 2024:

(1) See “NON-GAAP FINANCIAL MEASURES” on page 92.

Bamboo Results—Three Months Ended September 30, 2025 versus Three Months Ended September 30, 2024

Bamboo reported commission and fee revenues of $64 million and pre-tax income of $15 million in the third quarter of 2025 compared to commission and fee revenues of $43 million and pre-tax income of $16 million in the third quarter of 2024. Bamboo reported MGA pre-tax income of $15 million and MGA adjusted EBITDA of $28 million in the third quarter of 2025 compared to MGA pre-tax income of $14 million and MGA adjusted EBITDA of $19 million in the third quarter of 2024.

Bamboo’s estimates for losses to its programs from the January 2025 California wildfires remain unchanged at approximately $160 million as of September 30, 2025.

Bamboo Results—Nine Months Ended September 30, 2025 versus Nine Months Ended September 30, 2024

Bamboo reported commission and fee revenues of $167 million and pre-tax income of $37 million in the first nine months of 2025 compared to commission and fee revenues of $97 million and pre-tax income of $23 million in the first nine months of 2024. Bamboo reported MGA pre-tax income of $40 million and MGA adjusted EBITDA of $74 million in the first nine months of 2025 compared to MGA pre-tax income of $21 million and MGA adjusted EBITDA of $37 million in the first nine months of 2024.

Managed Premiums

Managed premiums represent the total premiums placed by Bamboo during the period. Managed premiums were $221 million in the third quarter of 2025 compared to $148 million in the third quarter of 2024. Managed premiums were $558 million in the first nine months of 2025 compared to $358 million in the first nine months of 2024. The increase in managed premiums was driven by growth in the renewal book as well as new business volume. Growth in the renewal book was driven by strong client policy retention rates as well as approved rate increases that went into effect in the first quarter of 2025. In the third quarter and first nine months of 2025, new business volume decreased year-over-year due to risk aggregation limits instituted by Bamboo on its largest program. However, in the third quarter of 2025, new business volume increased quarter-over-quarter for the second consecutive quarter as Bamboo continued to launch additional fronted programs that will enable new business growth over the rest of the year. Bamboo also launched a homeowners program in Texas in the third quarter.

The following table presents Bamboo’s managed premiums for the three and nine months ended September 30, 2025 and 2024:

Capacity Providers

During April 2025, Bamboo renewed its largest program for the treaty year ending April 1, 2026 on favorable terms, with strong demand from new and renewing reinsurance partners. Under the renewed terms, Bamboo MGA’s commission levels continue to be based on a sliding scale tied primarily to its attritional loss ratio. Bamboo also expanded its number of reinsurance partners on the program. Bamboo has continued to expand its total number of third-party Capacity Providers throughout the year. As of September 30, 2025, the insurance risk for Bamboo’s programs was supported by 28 third-party Capacity Providers.

Distinguished

On September 2, 2025, White Mountains acquired a controlling financial interest in Distinguished. White Mountains funded the Distinguished Transaction through a combination of cash on hand and new borrowings by Distinguished. White Mountains paid $224 million of cash consideration, and Distinguished borrowed $50 million of incremental debt as part of the transaction. The consideration is subject to customary purchase price adjustments. At closing, White Mountains owned 55.5%, inclusive of its 1.7% previously-held interest, of Distinguished on a basic units outstanding basis (43.6% on a fully-diluted/fully-converted basis, taking account of management’s equity incentives), while Distinguished management owned 4.2% of the basic units outstanding (24.7% on a fully-diluted/fully-converted basis). See Note 2 — “Significant Transactions.”

Distinguished is a full-service MGA and program administrator for specialty property and casualty insurance. Distinguished places insurance across a diversified portfolio of programs broadly grouped into two verticals. The ScaleCo vertical consists of established programs, primarily focused on real estate and hospitality end markets. The GrowthCo vertical consists of start-up programs, focused on a diversified set of specialty property and casualty insurance products across multiple industries. On behalf of its insurance carrier partners, Distinguished typically manages all aspects of the placement process, including product development, marketing, underwriting and policy issuance. Distinguished earns commissions based on the volume and profitability of the insurance that it places. Distinguished does not retain insurance risk.

The following table presents the components of GAAP net income (loss), ScaleCo net income (loss), ScaleCo EBITDA and ScaleCo adjusted EBITDA included in White Mountains’s Distinguished segment for the period from September 2, 2025, the date of acquisition, through September 30, 2025:

(1) See “NON-GAAP FINANCIAL MEASURES” on page 92.

Distinguished Results – Period From September 2, 2025 through September 30, 2025

Distinguished reported commission and fee revenues of $14 million, pre-tax loss of $3 million, and ScaleCo adjusted EBITDA of $1 million for the period from September 2, 2025, the date of acquisition, through September 30, 2025.

Managed Premiums and Commissions and Fee Revenues

Managed premiums, which represent the total premiums placed by Distinguished, were $43 million for the period from September 2, 2025 through September 30, 2025. The following table presents the managed premiums and commission and fee revenues by vertical for the period from September 2, 2025 through September 30, 2025:

82

Other Operations

The following table presents the components of pre-tax income (loss) included in White Mountains’s Other Operations for the three and nine months ended September 30, 2025 and 2024:

Other Operations Results—Three Months Ended September 30, 2025 versus Three Months Ended September 30, 2024

White Mountains’s Other Operations reported pre-tax income (loss) of $(25) million in the third quarter of 2025 compared to $108 million in the third quarter of 2024. White Mountains’s Other Operations reported unrealized investment gains from its investment in MediaAlpha of $8 million in the third quarter of 2025 compared to $88 million in the third quarter of 2024. Excluding MediaAlpha, White Mountains’s Other Operations reported net realized and unrealized investment gains of $15 million in the third quarter of 2025 compared to $30 million in the third quarter of 2024. The decrease in net realized and unrealized investment gains was driven primarily by lower gains from common equity securities, due to the sale of White Mountains’s portfolio of ETFs in the first six months of 2025 in preparation for capital deployments at BroadStreet and Distinguished, and lower gains from fixed income investments. White Mountains’s Other Operations reported net investment income of $6 million in the third quarter of 2025 compared to $10 million in the third quarter of 2024. See Summary of Investment Results on page 84.

White Mountains’s Other Operations reported other revenues of $69 million in the third quarter of 2025 compared to $15 million in the third quarter of 2024. White Mountains’s Other Operations reported cost of sales of $55 million in the third quarter of 2025 compared to $8 million in the third quarter of 2024. The increases in other revenues and cost of sales were driven primarily by the acquisition of Enterprise Solutions in the second quarter of 2025.

White Mountains’s Other Operations reported general and administrative expenses of $72 million in the third quarter of 2025 compared to $33 million in the third quarter of 2024. The increase in general and administrative expenses was driven primarily by higher incentive compensation costs, largely in connection with the Bamboo transaction, parent company transaction costs as well as the acquisition of Enterprise Solutions. Other Operations general and administrative expenses in the third quarter of 2025 included $44 million of parent company compensation and benefits compared to $16 million in the third quarter of 2024.

The Bamboo CRV reported $2 million of pre-tax income in the third quarter of 2025 compared to $3 million in the third quarter of 2024. The Bamboo CRV’s results included earned premiums of $3 million, loss and LAE of $1 million and acquisition expenses of $1 million in the third quarter of 2025 compared to earned premiums of $11 million, loss and LAE of $4 million and acquisition expenses of $5 million in the third quarter of 2024. During the second quarter of 2025, White Mountains renewed the Bamboo CRV for the 2025 treaty year at a commitment of up to $10 million, down from $30 million in the prior year due to strong demand from third-party Capacity Providers.

Other Operations Results—Nine Months Ended September 30, 2025 versus Nine Months Ended September 30, 2024

White Mountains’s Other Operations reported pre-tax income (loss) of $(48) million in the first nine months of 2025 compared to $157 million in the first nine months of 2024. White Mountains’s Other Operations reported unrealized investment gains from its investment in MediaAlpha of $2 million in the first nine months of 2025 compared to net realized and unrealized investment gains of $160 million in the first nine months of 2024. Excluding MediaAlpha, White Mountains’s Other Operations reported net realized and unrealized investment gains of $50 million in the first nine months of 2025 compared to $60 million in the first nine months of 2024. The decrease in net realized and unrealized investment gains was driven primarily by lower gains from common equity securities, due to the sale of White Mountains’s portfolio of ETFs in the first six months of 2025 in preparation for capital deployments at BroadStreet and Distinguished. White Mountains’s Other Operations reported net investment income of $25 million in the first nine months of 2025 compared to $28 million in the first nine months of 2024. See Summary of Investment Results on page 84.

White Mountains’s Other Operations reported other revenues of $140 million in the first nine months of 2025 compared to $44 million in the first nine months of 2024. White Mountains’s Other Operations reported cost of sales of $105 million in the first nine months of 2025 compared to $22 million in the first nine months of 2024. The increases in other revenues and cost of sales were driven primarily by the acquisition of Enterprise Solutions in the second quarter of 2025.

White Mountains’s Other Operations reported general and administrative expenses of $162 million in the first nine months of 2025 compared to $126 million in the first nine months of 2024. The increase in general and administrative expenses was driven primarily by higher incentive compensation costs, largely in connection with the Bamboo transaction, parent company transaction costs as well as the acquisition of Enterprise Solutions. Other Operations general and administrative expenses in the first nine months of 2025 included $81 million for parent company compensation and benefits compared to $67 million in the first nine months of 2024.

The Bamboo CRV reported $6 million of pre-tax loss in the first nine months of 2025 compared to $5 million of pre-tax income in the first nine months of 2024. The Bamboo CRV’s results included earned premiums of $19 million, loss and LAE of $19 million and acquisition expenses of $7 million in the first nine months of 2025 compared to earned premiums of $20 million, loss and LAE of $8 million and acquisition expenses of $7 million in the first nine months of 2024. Loss and LAE in the first nine months of 2025 included approximately $12 million related to the January 2025 California wildfires. Since its inception on April 1, 2024 through September 30, 2025, the Bamboo CRV has generated pre-tax income of $3 million, which included $2 million for the 2025 underwriting year and $1 million for the 2024 underwriting year.

II. Summary of Investment Results

White Mountains’s total investment results include results from all segments. For purposes of discussing rates of return, percentages are presented gross of management fees and trading expenses.

Effective July 1, 2024, White Mountains no longer consolidates BAM. Through June 30, 2024, White Mountains’s consolidated financial statements included BAM’s investment results. See Note 2 — “Significant Transactions.”

Gross Investment Returns and Benchmark Returns

The following table presents the pre-tax time-weighted investment returns for White Mountains’s consolidated portfolio, for the three and nine months ended September 30, 2025 and 2024:

(1) See “NON-GAAP FINANCIAL MEASURES” on page 92.

Investment Returns—Three and Nine Months Ended September 30, 2025 versus Three and Nine Months Ended September 30, 2024

White Mountains’s total consolidated portfolio return on invested assets was 2.1% in the third quarter of 2025, which included $8 million of unrealized investment gains from White Mountains’s investment in MediaAlpha. Excluding MediaAlpha, the total consolidated portfolio return on invested assets was 2.0% in the third quarter of 2025, driven primarily by net investment income and net unrealized investment gains from the other long-term investments and fixed income portfolios. White Mountains’s total consolidated portfolio return on invested assets was 4.6% in the third quarter of 2024, which included $88 million of unrealized investment gains from White Mountains’s investment in MediaAlpha. Excluding MediaAlpha, the total consolidated portfolio return on invested assets was 3.3% in the third quarter of 2024, driven primarily by net investment income and net unrealized investment gains from the fixed income and other long-term investments portfolios.

White Mountains’s total consolidated portfolio return on invested assets was 6.6% in the first nine months of 2025, which included $2 million of unrealized investment gains from White Mountains’s investment in MediaAlpha. Excluding MediaAlpha, the total consolidated portfolio return on invested assets was 6.8% in the first nine months of 2025, driven primarily by net investment income and net unrealized investment gains from the other long-term investments and fixed income portfolios. White Mountains’s total consolidated portfolio return on invested assets was 9.4% in the first nine months of 2024, which included $160 million of net realized and unrealized investment gains from White Mountains’s investment in MediaAlpha. Excluding MediaAlpha, the total consolidated portfolio return on invested assets was 6.9% in the first nine months of 2024, driven primarily by net investment income and net unrealized investment gains from the fixed income, common equity securities and other-long term investments portfolios.

Fixed Income Results

White Mountains’s fixed income portfolio, including short-term investments, totaled $3.8 billion and $3.5 billion as of September 30, 2025 and December 31, 2024, which represented 54% of total invested assets for each period. The duration of White Mountains’s fixed income portfolio, including short-term investments, was 1.6 years and 1.9 years as of September 30, 2025 and December 31, 2024. White Mountains’s fixed income portfolio includes fixed maturity and short-term investments held on deposit or as collateral. See Note 3 — “Investment Securities.”

White Mountains’s fixed income portfolio returned 1.5% in the third quarter of 2025 compared to 2.9% in the third quarter of 2024, underperforming the Bloomberg U.S. Intermediate Aggregate Index returns of 1.8% and 4.6% for the comparable periods. Results in the third quarter of 2025 and 2024 were driven primarily by net investment income and net unrealized investment gains due to the effect of the decline in interest rates on White Mountains’s short duration fixed income portfolio.

White Mountains’s fixed income portfolio returned 4.8% in the first nine months of 2025 compared to 4.6% in the first nine months of 2024, underperforming and in line with the Bloomberg U.S. Intermediate Aggregate Index returns of 6.0% and 4.6% for the comparable periods. Results in the first nine months of 2025 and 2024 were driven primarily by net investment income and net unrealized investment gains due to the effect of the decline in interest rates on White Mountains’s short duration fixed income portfolio.

Common Equity Securities, Investment in MediaAlpha and Other Long-Term Investments Results

White Mountains’s portfolio of common equity securities, its investment in MediaAlpha and other long-term investments totaled $3.2 billion and $3.0 billion as of September 30, 2025 and December 31, 2024, which represented 46% of total invested assets for each period. See Note 3 — “Investment Securities.”

White Mountains’s portfolio of common equity securities, its investment in MediaAlpha and other long-term investments returned 2.8% in the third quarter of 2025, which included $8 million of unrealized investment gains from White Mountains’s investment in MediaAlpha. White Mountains’s portfolio of common equity securities and other long-term investments returned 2.7% in the third quarter of 2025. White Mountains’s portfolio of common equity securities, its investment in MediaAlpha and other long-term investments returned 6.5% in the third quarter of 2024, which included $88 million of unrealized investment gains from White Mountains’s investment in MediaAlpha. White Mountains’s portfolio of common equity securities and other long-term investments returned 3.8% in the third quarter of 2024.

White Mountains’s portfolio of common equity securities, its investment in MediaAlpha and other long-term investments returned 8.9% in the first nine months of 2025, which included $2 million of unrealized investment gains from White Mountains’s investment in MediaAlpha. White Mountains’s portfolio of common equity securities and other long-term investments returned 9.5% in the first nine months of 2025. White Mountains’s portfolio of common equity securities, its investment in MediaAlpha and other long-term investments returned 15.1% in the first nine months of 2024, which included $160 million of net realized and unrealized investment gains from White Mountains’s investment in MediaAlpha. White Mountains’s portfolio of common equity securities and other long-term investments returned 10.1% in the first nine months of 2024.

White Mountains’s portfolio of common equity securities generally consists of international listed equity funds, primarily held at Ark, and passive ETFs. White Mountains’s ETFs seek to provide investment results generally corresponding to the performance of the S&P 500 Index. White Mountains’s portfolio of common equity securities totaled $438 million and $650 million as of September 30, 2025 and December 31, 2024. The decrease in common equity securities in the first nine months of 2025 was due to the sale of White Mountains’s ETF portfolio in preparation for capital deployments at BroadStreet and Distinguished. See Note 2 — “Significant Transactions.”

White Mountains’s portfolio of common equity securities returned 0.6% in the third quarter of 2025 compared to 4.0% in the third quarter of 2024, underperforming the S&P 500 Index returns of 8.1% and 5.9% for the comparable periods. White Mountains’s portfolio of common equity securities returned 7.0% in the first nine months of 2025 compared to 12.1% in the first nine months of 2024, underperforming the S&P 500 Index returns of 14.8% and 22.1% for the comparable periods. The underperformance in each period was driven primarily by certain international listed equity funds that employ a market neutral strategy.

White Mountains maintains a portfolio of other long-term investments that consists primarily of unconsolidated entities, including Kudu’s Participation Contracts, private equity funds and hedge funds, a bank loan fund, Lloyd’s trust deposits, ILS funds and private debt instruments. White Mountains’s portfolio of other long-term investments totaled $2.6 billion and $2.2 billion as of September 30, 2025 and December 31, 2024.

White Mountains’s portfolio of other long-term investments returned 3.1% in the third quarter of 2025 compared to 3.7% in the third quarter of 2024. Investment returns for the third quarter of 2025 were driven primarily by net investment income and net unrealized investment gains from Kudu’s Participation Contracts, as well as net investment income and net realized and unrealized investments gains from private equity funds and hedge funds. Investment returns for the third quarter of 2024 were driven primarily by net investment income and net unrealized investment gains from Kudu’s Participation Contracts and private equity funds, as well as net unrealized investment gains from ILS funds.

White Mountains’s portfolio of other long-term investments returned 9.7% in the first nine months of 2025 compared to 9.5% in the first nine months of 2024. Investment returns for the first nine months of 2025 were driven primarily by net investment income and net unrealized investment gains from Kudu’s Participation Contracts, as well as net investment income and net realized and unrealized investment gains from certain unconsolidated entities, private equity funds, hedge funds and ILS funds. Investment returns for the first nine months of 2024 were driven primarily by net investment income and net realized and unrealized investment gains from Kudu’s Participation Contracts, as well as net investment income and net unrealized gains from ILS funds.

Foreign Currency Exposure

As of September 30, 2025, White Mountains had foreign currency exposure on $402 million of net assets, primarily related to Ark/WM Outrigger’s non-U.S. contracts, Kudu’s non-U.S. Participation Contracts and a private debt instrument, as well as certain other foreign consolidated and unconsolidated entities.

The following table presents the fair value of White Mountains’s foreign denominated net assets (liabilities) by segment as of September 30, 2025:

$ in Millions Currency

86

III. Income Taxes

As of September 30, 2025, the primary jurisdictions in which the Company’s subsidiaries and branches operated and were subject to tax are Israel, Luxembourg, the United Kingdom and the United States.

On December 27, 2023, Bermuda enacted a 15% corporate income tax that became effective on January 1, 2025. The Bermuda legislation defers the effective date for five years, for Bermuda companies in consolidated groups that meet certain requirements. To qualify for the deferral, generally the group must (i) have consolidated affiliates and permanent establishments in six or fewer countries, (ii) have no more than €50 million of net tangible assets outside of the country where the group has the largest amount of net tangible assets and (iii) not have a consolidated Bermuda affiliate or Bermuda permanent establishment directly or indirectly owned by a parent entity that is subject to the Income Inclusion Rule of Pillar Two in any jurisdiction. White Mountains expects to meet the requirements to be exempt from the Bermuda corporate income tax until January 1, 2030. The Bermuda legislation also provides for an economic transition adjustment that will reduce future years’ taxable income. Under GAAP, this economic transition adjustment was required to be recognized as a net deferred tax asset as of December 31, 2023. Accordingly, White Mountains recorded a net deferred tax asset of $68 million, with $51 million attributable to Ark and $17 million attributable to HG Global. As a result of the deconsolidation of BAM in the third quarter of 2024, the BAM Surplus Notes were recorded at fair value, which resulted in the reversal of a $5 million deferred tax liability related to the economic transition adjustment. As of September 30, 2025, the net deferred tax asset related to the economic transition adjustment was $73 million, with $51 million attributable to Ark and $22 million attributable to HG Global.

On September 12, 2025, the Bermuda Corporate Income Tax Agency released draft legislation for public comment that includes a proposed amendment to the economic transition adjustment. If enacted in its current form, the proposed legislation would result in a $5 million increase to White Mountains’s net deferred tax asset related to the economic transition adjustment. On September 4, 2025, the Bermuda Government issued draft legislation for public comment that would make available refundable tax credits to qualifying Bermuda entities that are designed to encourage employment, training and local expenditure in Bermuda. Under the proposal, a Bermuda company may qualify for a refundable tax credit in a given year even if it is not subject to the Bermuda corporate income tax. If the proposed legislation is enacted in its current form, White Mountains expects to qualify for certain refundable tax credits beginning in 2025.

On December 15, 2022, European Union Member States voted to adopt the EU Minimum Tax Directive in conformity with the OECD Pillar Two initiative. The Pillar Two initiative includes a set of model rules that are generally designed to impose a top-up tax on a large multinational enterprise group to the extent the group is not subject to an effective tax rate of at least 15% in each jurisdiction in which the group has a consolidated affiliate or permanent establishment. The EU Minimum Tax Directive required European Union Member States to enact conforming law by December 31, 2023. The main rule of the EU Minimum Tax Directive, the Income Inclusion Rule (“IIR”), was to become effective for fiscal years beginning on or after December 31, 2023, while the Undertaxed Profits Rule (“UTPR”) was to become effective for fiscal years beginning on or after December 31, 2024. The EU Minimum Tax Directive also permits European Union Member States to elect to apply a Qualified Domestic Minimum Top-up Tax (“QDMTT”) for fiscal years beginning on or after December 31, 2023.

On December 20, 2023, Luxembourg enacted conforming Pillar Two legislation including the IIR, UTPR and the QDMTT. Additional legislation addressing the applicability of the QDMTT was enacted on December 23, 2024. The Luxembourg Pillar Two rules defer the effective date of the QDMTT and UTPR until fiscal years beginning on or after December 31, 2028 and 2029, respectively, for Luxembourg companies in consolidated groups with a non-EU parent company that meet certain requirements. To qualify for the deferral, generally the group must (i) have consolidated affiliates and permanent establishments in six or fewer countries and (ii) have no more than €50 million of net tangible assets outside of the country where the group has the largest amount of net tangible assets. White Mountains expects to meet the requirements to be exempt from the Luxembourg QDMTT and UTPR until January 1, 2029 and 2030, respectively.

On July 11, 2023, the U.K. enacted conforming legislation adopting the Pillar Two IIR and QDMTT which became effective for fiscal years beginning on or after December 31, 2023. On March 20, 2025, the U.K. enacted legislation adopting the Pillar Two UTPR effective for fiscal years beginning on or after December 31, 2024. Under the legislation, the effective date of the UTPR is deferred until fiscal years beginning on or after December 31, 2029 for U.K. companies in consolidated groups with a non-EU parent company that meet certain requirements. To qualify for the deferral, generally the group must (i) have consolidated affiliates and permanent establishments in six or fewer countries and (ii) have no more than €50 million of net tangible assets outside of the country where the group has the largest amount of net tangible assets. White Mountains expects to meet the requirements to be exempt from the U.K. UTPR until January 1, 2030.

On January 15, 2025, the OECD released administrative guidance on its Pillar Two model rules (the “January 2025 OECD Administrative Guidance”). The January 2025 OECD Administrative Guidance provides that, subject to limited exceptions, deferred tax expense attributable to deferred tax assets resulting from the introduction of a new corporate income tax after November 30, 2021 is to be excluded when assessing whether a multinational enterprise group has an effective tax rate of at least 15% in the jurisdiction that adopted the corporate income tax. Deferred tax assets associated with the economic transition adjustment recognized under the Bermuda corporate income tax are expected to be within the scope of the January 2025 OECD Administrative Guidance. Draft legislation has been proposed in both the U.K. and Luxembourg that would adopt the January 2025 OECD Administrative Guidance under the domestic laws of each country. As of September 30, 2025, neither the U.K. nor Luxembourg had enacted the proposed legislation, and no changes had been enacted with respect to the Bermuda corporate income tax to repeal or otherwise limit the economic transition adjustment. Accordingly, under GAAP, White Mountains is required to maintain the net deferred tax asset attributable to the economic transition adjustment as of September 30, 2025. Currently, the impact of any potential changes in response to the January 2025 OECD Administrative Guidance is uncertain, but may result in the elimination of the net deferred tax asset related to the economic transition adjustment.

On July 4, 2025, the U.S. enacted the One Big Beautiful Bill Act (“OBBBA”). White Mountains does not expect the OBBBA to have a material effect on its financial statements.

White Mountains’s income tax expense related to pre-tax income from continuing operations for the three and nine months ended September 30, 2025 represented an effective tax rate of 10% and 9%. The effective tax rate was different from the U.S. statutory rate of 21.0%, driven primarily by full year forecasted income in jurisdictions with lower tax rates than the United States.

White Mountains’s income tax expense related to pre-tax income from continuing operations for the three and nine months ended September 30, 2024 represented an effective tax rate of 5% and 7%. The effective tax rate was different from the U.S. statutory rate of 21.0%, driven primarily by full year forecasted income in jurisdictions with lower tax rates than the United States.

LIQUIDITY AND CAPITAL RESOURCES

Operating Cash and Short-term Investments

Holding Company Level

The primary sources of cash for the Company and certain of its intermediate holding companies are expected to be distributions from its insurance, reinsurance and other operating subsidiaries, net investment income, proceeds from sales, repayments and maturities of investments, borrowings from credit facilities, capital raising activities and, from time to time, proceeds from sales of operating subsidiaries. The primary uses of cash are expected to be general and administrative expenses, purchases of investments, payments to tax authorities, payments on and repurchases/retirements of debt obligations, dividend payments to holders of the Company’s common shares, distributions to noncontrolling interest holders of consolidated subsidiaries, contributions to operating subsidiaries and, from time to time, purchases of operating subsidiaries and repurchases of the Company’s common shares.

Operating Subsidiary Level

The primary sources of cash for White Mountains’s insurance, reinsurance and other operating subsidiaries are expected to be premium and fee collections, commissions, net investment income, proceeds from sales, repayments and maturities of investments, contributions from holding companies, borrowings from credit facilities, and capital raising activities. The primary uses of cash are expected to be claim payments, policy acquisition costs, general and administrative expenses, broker commission expenses, cost of sales, purchases of investments, payments to tax authorities, payments on and repurchases/retirements of debt obligations, distributions to holding companies, distributions to noncontrolling interest holders and, from time to time, purchases of operating subsidiaries.

Both internal and external forces influence White Mountains’s financial condition, results of operations and cash flows. Premium and fee collections, investment returns, claim payments and cost of sales may be impacted by changing rates of inflation and other economic conditions. Some time may lapse between the occurrence of an insured loss, the reporting of the loss to White Mountains’s insurance and reinsurance operating subsidiaries and the settlement of the liability for that loss. The exact timing of the payment of losses cannot be predicted with certainty. White Mountains’s insurance and reinsurance operating subsidiaries maintain portfolios of invested assets with varying maturities and a substantial amount of cash and short-term investments to provide adequate liquidity for the payment of claims.

Management believes that White Mountains’s cash balances, cash flows from operations and routine sales and maturities of investments are adequate to meet expected cash requirements for the foreseeable future at both a holding company and insurance, reinsurance and other operating subsidiary level.

Dividend Capacity

Following is a description of the dividend capacity of White Mountains’s insurance and reinsurance and other operating subsidiaries:

Ark/WM Outrigger

During any 12-month period, GAIL, a class 4 licensed Bermuda insurer, has the ability to (i) make capital distributions of up to 15% of its total statutory capital per the previous year’s statutory financial statements, or (ii) make dividend payments of up to 25% of its total statutory capital and surplus per the previous year’s statutory financial statements, without prior approval of Bermuda regulatory authorities. Accordingly, GAIL will have the ability to pay a dividend of up to $337 million during 2025, which is equal to 25% of its statutory capital and surplus of $1,347 million as of December 31, 2024, subject to meeting all appropriate liquidity and solvency requirements. During the nine months ended September 30, 2025, GAIL did not pay any dividends to its immediate parent.

During the nine months ended September 30, 2025, Ark declared and paid a $41 million dividend to shareholders, including $30 million that was paid to White Mountains. As of September 30, 2025, Ark and its intermediate holding companies had $9 million of net unrestricted cash and short-term investments outside of its regulated and unregulated insurance and reinsurance operating subsidiaries.

WM Outrigger Re is a special purpose insurer subject to regulation and supervision by the BMA. WM Outrigger Re does not require regulatory approval to pay dividends; however, its dividend capacity is limited to amounts held outside of the collateral trust pursuant to its reinsurance agreement with GAIL. As of September 30, 2025, WM Outrigger Re had less than $1 million of net unrestricted cash held outside the collateral trust. As of September 30, 2025, WM Outrigger Re had $220 million of statutory capital and surplus and $228 million of assets held in the collateral trusts pursuant to the reinsurance agreement with GAIL. During the nine months ended September 30, 2025, White Mountains received a distribution of $6 million from WM Outrigger Re.

HG Global

As of September 30, 2025, HG Global had $619 million face value of preferred shares outstanding, of which White Mountains owned 96.9%. Holders of the HG Global preferred shares are entitled to receive cumulative dividends at a fixed annual rate of 6.0% on a quarterly basis, payable when and if declared by HG Global. As of September 30, 2025, HG Global has accrued $526 million of dividends payable to holders of its preferred shares, $511 million of which is payable to White Mountains and is eliminated in consolidation. As of September 30, 2025, HG Global and its subsidiaries had $10 million of net unrestricted cash and short-term investments outside of HG Re.

HG Re is a special purpose insurer subject to regulation and supervision by the BMA. HG Re does not require regulatory approval to pay dividends; however, its dividend capacity is limited to amounts held outside of the Collateral Trusts. As of September 30, 2025, HG Re had $3 million of net unrestricted cash and short-term investments. As of September 30, 2025, HG Re had $178 million of accrued interest on the BAM Surplus Notes held outside the Collateral Trusts. As of September 30, 2025, HG Re had $770 million of statutory capital and surplus and $1,002 million of assets held in the Collateral Trusts.

HG Global has two primary sources of cash flows: (i) interest payments on the BAM Surplus Notes that are made outside the Collateral Trusts and (ii) releases of excess balances from the Collateral Trusts. During the nine months ended September 30, 2025, HG Global received cash payments of principal and interest on the BAM Surplus Notes totaling $8 million. During the nine months ended September 30, 2025, HG Re received a distribution from the Supplemental Trust of $38 million, which consisted of an assignment of accrued interest on the BAM Surplus Notes of $23 million and a cash distribution of $15 million. See Note 10 — “Municipal Bond Guarantee Reinsurance.”

Kudu

During the nine months ended September 30, 2025, Kudu distributed $11 million to unitholders, substantially all of which was paid to White Mountains. As of September 30, 2025, Kudu had $21 million of net unrestricted cash and short-term investments.

Bamboo

During the nine months ended September 30, 2025, Bamboo paid $109 million of dividends to unitholders, $78 million of which were paid to White Mountains. As of September 30, 2025, Bamboo had $52 million of net unrestricted cash and short-term investments outside of the Bamboo Captive.

The Bamboo Captive is a protected cell captive domiciled in the state of Arizona and is subject to regulation and supervision by the Arizona Department of Insurance and Financial Institutions (“Arizona DIFI”). As an Arizona-domiciled protected cell, the Bamboo Captive is required to maintain $0.5 million of minimum capital. As of December 31, 2024, the Bamboo Captive had statutory capital and surplus of $7 million. The Bamboo Captive cannot pay any dividends without the approval of the Arizona DIFI. During the nine months ended September 30, 2025, the Bamboo Captive did not pay any dividends to its immediate parent. As of September 30, 2025, the Bamboo Captive had $4 million of net unrestricted cash and short-term investments and $39 million of assets held as collateral pursuant to its reinsurance agreements.

Distinguished

For the period from September 2, 2025, the date of acquisition, through September 30, 2025, Distinguished did not make any distributions to its unitholders. As of September 30, 2025, Distinguished had $16 million of net unrestricted cash and short-term investments and $48 million of short-term investments held on deposit on behalf of Distinguished’s insurance carrier partners and certain insureds.

Other Operations

During the nine months ended September 30, 2025, White Mountains paid a $3 million common share dividend. As of September 30, 2025, the Company and its intermediate holding companies had $366 million of net unrestricted cash, short-term investments and fixed maturity investments, $203 million of MediaAlpha common stock and $288 million of private equity and hedge funds, ILS funds and certain unconsolidated entities.

During the nine months ended September 30, 2025, White Mountains received a distribution of $17 million from the Bamboo CRV.

Financing

The following table presents White Mountains’s capital structure as of September 30, 2025 and December 31, 2024:

$ in Millions

(1) See Note 7 — “Debt” for details of debt arrangements.

(2) Net of unamortized issuance costs and, where applicable, the original issue discount.

Management believes that White Mountains has the flexibility and capacity to obtain funds externally through debt or equity financing on both a short-term and long-term basis. However, White Mountains can provide no assurance that, if needed, it would be able to obtain additional debt or equity financing on satisfactory terms, if at all.

It is possible that, in the future, one or more of the rating agencies may lower White Mountains’s existing ratings. If one or more of its ratings were lowered, White Mountains could incur higher borrowing costs on future borrowings, and its ability to access the capital markets could be impacted.

Covenant Compliance

As of September 30, 2025, White Mountains was in compliance in all material respects with all of the covenants under its debt instruments.

Share Repurchase Programs

The Company’s Board of Directors has authorized the Company to repurchase its common shares from time to time, subject to market conditions. Shares may be repurchased on the open market or through privately negotiated transactions. The repurchase authorizations do not have a stated expiration date. As of September 30, 2025, White Mountains may repurchase an additional 301,014 shares under these Board authorizations. In addition, from time to time, White Mountains has also repurchased its common shares through self-tender offers that were separately approved by its Board of Directors.

During the nine months ended September 30, 2025, White Mountains repurchased and retired 5,097 of its common shares for $10 million at an average share price of $1,945, which was approximately 105% of White Mountains’s book value per share as of September 30, 2025. During the nine months ended September 30, 2024, White Mountains repurchased and retired 5,269 of its common shares for $8 million at an average share price of $1,505, which was approximately 84% of White Mountains’s book value per share as of September 30, 2024. All of the shares White Mountains repurchased in the first nine months of 2025 and 2024 were to satisfy employee income tax withholding pursuant to employee benefit plans, which do not reduce the amount available under the Board repurchase authorizations.

Cash Flows

Detailed information concerning White Mountains’s cash flows from continuing operations during the nine months ended September 30, 2025 and 2024 follows:

Cash flows from operations for the nine months ended September 30, 2025 and September 30, 2024

Net cash provided from operations was $497 million for the nine months ended September 30, 2025 compared to $523 million for the nine months ended September 30, 2024. The decrease in cash provided from operations was driven primarily by two new deployments at Kudu in 2025, partially offset by an increase in cash provided from operations at Ark/WM Outrigger Re. As of September 30, 2025, the Company and its intermediate holding companies had $366 million of net unrestricted cash, short-term investments and fixed maturity investments, $203 million of MediaAlpha common stock and $288 million of private equity funds, hedge funds, ILS funds and certain unconsolidated entities.

Cash flows from investing and financing activities for the nine months ended September 30, 2025

Financing and Other Capital Activities

During the nine months ended September 30, 2025, the Company declared and paid a $3 million cash dividend to its common shareholders.

During the nine months ended September 30, 2025, White Mountains repurchased and retired 5,097 of its common shares for $10 million, all of which were to satisfy employee income tax withholding pursuant to employee benefit.

During the nine months ended September 30, 2025, Kudu borrowed $37 million in term loans under the Kudu Credit Facility.

During the nine months ended September 30, 2025, White Mountains contributed $15 million to Kudu, which was used to repurchase certain management equity incentives that were then replaced with new equity incentive units.

During the nine months ended September 30, 2025, Bamboo borrowed $110 million in term loans under the Bamboo Credit Facility.

Acquisitions and Dispositions

On April 1, 2025, White Mountains closed on its acquisition of Enterprise Solutions. White Mountains paid $58 million of cash consideration, which included a post-acquisition contribution of $2 million, and Enterprise Solutions borrowed $15 million in new debt as part of the transaction.

On July 18, 2025, White Mountains deployed $150 million into BroadStreet through the BroadStreet SPV.

On September 2, 2025, White Mountains closed its acquisition of Distinguished. White Mountains paid $224 million of cash consideration and Distinguished borrowed $50 million of incremental debt as part of the transaction.

Cash flows from investing and financing activities for the nine months ended September 30, 2024

Financing and Other Capital Activities

During the nine months ended September 30, 2024, the Company declared and paid a $3 million cash dividend to its common shareholders.

During the nine months ended September 30, 2024, White Mountains repurchased and retired 5,269 of its common shares for $8 million, all of which were to satisfy employee income tax withholding pursuant to employee benefit plans.

During the nine months ended September 30, 2024, Ark repaid the outstanding balance of $30 million and extinguished the Ark 2007 Subordinated Notes.

BAM received $26 million in MSC during the six months ended June 30, 2024, prior to its deconsolidation.

During the nine months ended September 30, 2024, Kudu borrowed $15 million in term loans under the Kudu Credit Facility.

Acquisitions and Dispositions

On January 2, 2024, White Mountains closed its acquisition of Bamboo in accordance with the terms of the Bamboo Merger Agreement, investing $297 million of equity into Bamboo, which included the contribution of $36 million to retire Bamboo’s legacy credit facility and the contribution of $20 million of primary capital.

NON-GAAP FINANCIAL MEASURES

This report includes 11 non-GAAP financial measures that have been reconciled from their most comparable GAAP financial measures.

Ark’s tangible book value

Ark’s tangible book value is a non-GAAP financial measure derived by adjusting GAAP book value to exclude goodwill, other intangible assets, the related deferred tax liability and the contingent consideration liability. The contingent consideration liability represents the estimated fair value of the additional shares that could be earned by management rollover shareholders if and to the extent that White Mountains achieves certain MOIC return thresholds. If earned, these additional shares would result in a reallocation of economics among Ark’s shareholders, which is reflected in the fair value of the contingent consideration liability recorded by White Mountains, but would have no impact on Ark’s stand-alone book value or tangible book value. White Mountains believes that this non-GAAP financial measure is useful to management and investors in evaluating Ark’s enterprise value. See page 71 for the reconciliation of Ark’s GAAP equity to tangible book value.

Kudu’s EBITDA and adjusted EBITDA

Kudu's EBITDA and adjusted EBITDA are non-GAAP financial measures. EBITDA is a non-GAAP financial measure that adds back interest expense on debt, income tax (expense) benefit, depreciation and amortization of other intangible assets to GAAP net income (loss). Adjusted EBITDA is a non-GAAP financial measure that excludes certain other items in GAAP net income (loss) in addition to those added back to calculate EBITDA. The items relate to (i) net realized and unrealized investment gains (losses) on Kudu's Participation Contracts, (ii) non-cash equity-based compensation expense and (iii) transaction expenses.

A description of each item follows:

• Net realized and unrealized investment gains (losses) - Represents net unrealized investment gains and losses on Kudu’s Participation Contracts, which are recorded at fair value under GAAP, and realized investment gains and losses recorded on Kudu’s Participation Contracts sold during the period.
• Non-cash equity-based compensation expense - Represents non-cash expenses related to Kudu’s management compensation that are settled with equity units in Kudu.
• Transaction expenses - Represents costs directly related to Kudu’s mergers and acquisitions activity, such as external lawyer, banker, consulting and placement agent fees, which are not capitalized and are expensed under GAAP.

White Mountains believes that these non-GAAP financial measures are useful to management and investors in evaluating Kudu’s performance. The reconciliation of Kudu’s GAAP net income (loss) to EBITDA and adjusted EBITDA is included on page 78.

Bamboo’s MGA pre-tax income (loss), MGA net income (loss), MGA EBITDA and MGA adjusted EBITDA

Bamboo’s MGA pre-tax income (loss), MGA net income (loss), MGA EBITDA and MGA adjusted EBITDA are non-GAAP financial measures.

MGA pre-tax income (loss) and MGA net income (loss) are non-GAAP financial measures that exclude the results of the Bamboo Captive, which is consolidated under GAAP, from Bamboo’s consolidated GAAP pre-tax income (loss) and net income (loss). The following table presents the reconciliation from Bamboo’s consolidated GAAP pre-tax income (loss) to MGA pre-tax income (loss) for the three and nine months ended September 30, 2025 and 2024:

MGA EBITDA is a non-GAAP financial measure that adds back interest expense on debt, income tax (expense) benefit, depreciation and amortization of other intangible assets to MGA net income (loss). MGA adjusted EBITDA is a non-GAAP financial measure that excludes certain other items in GAAP net income (loss) in addition to those added back to calculate MGA EBITDA. The items relate to (i) non-cash equity-based compensation expense, (ii) software implementation expenses, (iii) restructuring expenses and (iv) transaction expenses. A description of each item follows:

• Non-cash equity-based compensation expense - Represents non-cash expenses related to Bamboo’s management compensation that are settled with equity units in Bamboo.
• Software implementation expenses - Represents costs directly related to Bamboo’s implementation of new software.
• Restructuring expenses - Represents costs directly related to Bamboo’s corporate restructuring and capital planning activities.
• Transaction expenses - Represents costs directly related to the Bamboo Sale Transaction, including legal and consulting fees, which are not capitalized and are expensed under GAAP.

White Mountains believes that these non-GAAP financial measures are useful to management and investors in evaluating Bamboo’s performance. See page 80 for the reconciliation of Bamboo’s consolidated GAAP net income (loss) to MGA net income (loss), MGA EBITDA and MGA adjusted EBITDA.

Distinguished’s ScaleCo net income (loss), ScaleCo EBITDA and ScaleCo adjusted EBITDA

Distinguished’s ScaleCo net income (loss), ScaleCo EBITDA and ScaleCo adjusted EBITDA are non-GAAP financial measures. ScaleCo net income (loss) is a non-GAAP financial measure that excludes the results of the GrowthCo vertical, which is consolidated under GAAP, from Distinguished’s net income (loss). ScaleCo EBITDA is a non-GAAP financial measure that adds back interest expense on debt, income tax (expense) benefit, depreciation and amortization of other intangible assets to ScaleCo net income (loss). ScaleCo adjusted EBITDA is a non-GAAP financial measure that excludes the non-cash equity-based compensation expense in ScaleCo GAAP net income (loss) in addition to those items added back to calculate ScaleCo EBITDA. The non-cash equity-based compensation expense represents management compensation that is settled with equity units in Distinguished.

White Mountains believes that these non-GAAP financial measures are useful to management and investors in evaluating Distinguished’s performance. White Mountains also believes that excluding the results of the GrowthCo vertical, which Distinguished views as an investment in start-up programs, is useful to understanding the performance of Distinguished’s established programs. See page 82 for the reconciliation of Distinguished’s consolidated GAAP net income (loss) to ScaleCo net income (loss), ScaleCo EBITDA and ScaleCo adjusted EBITDA.

Total consolidated portfolio return excluding MediaAlpha

Total consolidated portfolio return excluding MediaAlpha is a non-GAAP financial measure that removes the net investment income and net realized and unrealized investment gains (losses) from White Mountains’s investment in MediaAlpha. White Mountains believes this measure to be useful to management and investors by showing the underlying performance of White Mountains’s investment portfolio without regard to White Mountains’s investment in MediaAlpha.

The following table presents return reconciliations from GAAP to the reported percentages for the three and nine months ended September 30, 2025 and 2024:

93

CRITICAL ACCOUNTING ESTIMATES

Refer to the Company’s 2024 Annual Report on Form 10-K for a complete discussion regarding White Mountains’s critical accounting estimates.

FORWARD-LOOKING STATEMENTS

This report may contain “forward-looking statements” within the meaning of Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934. All statements, other than statements of historical facts, included or referenced in this report which address activities, events or developments which White Mountains expects or anticipates will or may occur in the future are forward-looking statements. The words “could”, “will”, “believe”, “intend”, “expect”, “anticipate”, “project”, “estimate”, “predict” and similar expressions are also intended to identify forward-looking statements. These forward-looking statements include, among others, statements with respect to White Mountains’s:

• change in book value per share or return on equity;
• business strategy;
• financial and operating targets or plans;
• incurred loss and LAE and the adequacy of its loss and LAE reserves and related reinsurance;
• projections of revenues, income (or loss), earnings (or loss) per share, EBITDA, adjusted EBITDA, dividends, market share or other financial forecasts of White Mountains or its businesses;
• expansion and growth of its business and operations; and
• future capital expenditures.

These statements are based on certain assumptions and analyses made by White Mountains in light of its experience and perception of historical trends, current conditions and expected future developments, as well as other factors believed to be appropriate in the circumstances. However, whether actual results and developments will conform to its expectations and predictions is subject to risks and uncertainties that could cause actual results to differ materially from expectations, including:

• the risks that are described from time to time in White Mountains’s filings with the Securities and Exchange Commission, including but not limited to White Mountains’s 2024 Annual Report on Form 10-K;
• claims arising from catastrophic events, such as hurricanes, windstorms, earthquakes, floods, wildfires, tornadoes, tsunamis, severe weather, public health crises, terrorist attacks, war and war-like actions, explosions, infrastructure failures or cyber attacks;
• recorded loss reserves subsequently proving to have been inadequate;
• the market value of White Mountains’s investment in MediaAlpha;
• business opportunities (or lack thereof) that may be presented to it and pursued;
• actions taken by rating agencies, such as financial strength or credit ratings downgrades or placing ratings on negative watch;
• the continued availability of capital and financing;
• the continued availability of fronting and reinsurance capacity;
• deterioration of general economic, market or business conditions, including due to outbreaks of contagious disease and corresponding mitigation efforts;
• competitive forces, including the conduct of other insurers;
• changes in domestic or foreign laws or regulations, or their interpretation, applicable to White Mountains, its competitors or its customers; and
• other factors, most of which are beyond White Mountains’s control.

Consequently, all of the forward-looking statements made in this report are qualified by these cautionary statements, and there can be no assurance that the actual results or developments anticipated by White Mountains will be realized or, even if substantially realized, that they will have the expected consequences to, or effects on, White Mountains or its business or operations. White Mountains assumes no obligation to publicly update any such forward-looking statements, whether as a result of new information, future events or otherwise.

Refer to White Mountains’s 2024 Annual Report on Form 10-K and in particular Item 7A. - “Quantitative and Qualitative Disclosures About Market Risk.”

The Principal Executive Officer (“PEO”) and the Principal Financial Officer (“PFO”) of White Mountains have evaluated the effectiveness of its disclosure controls and procedures (as defined in Rule 13a-15(e) of the Exchange Act) as of September 30, 2025. Based on that evaluation, the PEO and PFO have concluded that White Mountains’s disclosure controls and procedures are adequate and effective.

There were no changes to White Mountains’s internal control over financial reporting that occurred during the third quarter of 2025 that have materially affected, or are reasonably likely to materially affect, White Mountains’s internal control over financial reporting.

There have been no material changes to any of the risk factors previously disclosed in the Registrant’s 2024 Annual Report on Form 10-K.