White Mountains Insurance Group Ltd: Form 10-Q for the period ended Jun 30, 2026

*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 89 for specific important factors that could cause actual results to differ materially from those contained in forward-looking statements.

The following discussion also includes eleven non-GAAP financial measures: (i) Ark’s tangible book value, (ii) Ark’s growth in tangible book value, (iii) Ark’s tangible capital, (iv) Kudu’s earnings before interest, taxes, depreciation and amortization (“EBITDA”), (v) Kudu’s adjusted EBITDA, (vi) Distinguished’s ScaleCo net income (loss), (vii) Distinguished’s ScaleCo EBITDA, (viii) Distinguished’s ScaleCo adjusted EBITDA, (ix) WTM Partners’s EBITDA, (x) WTM Partners’s adjusted EBITDA and (xi) total consolidated portfolio return excluding MediaAlpha. These non-GAAP financial measures have been reconciled from their most comparable GAAP financial measures on page 87. White Mountains believes these measures to be useful in evaluating White Mountains’s financial performance and condition.

RESULTS OF OPERATIONS FOR THE THREE AND SIX MONTHS ENDED JUNE 30, 2026 and 2025

Overview

White Mountains reported book value per share of $2,258 as of June 30, 2026, an increase of 4% in the second quarter of 2026 and 3% in the first six months of 2026, including dividends. Results in the second quarter and first six months of 2026 were driven primarily by strong operating company results and solid investment returns.

White Mountains reported book value per share of $1,804 as of June 30, 2025, an increase of 3% in both the second quarter and first six months of 2025, including dividends. Results in the second quarter and first six months of 2025 were driven primarily by solid operating company results and good investment returns.

Comprehensive income (loss) attributable to common shareholders was $199 million and $173 million in the second quarter and first six months of 2026 compared to $124 million and $159 million in the second quarter and first six months of 2025. Results in the second quarter and first six months of 2026 included $151 million and $161 million of net realized and unrealized investment gains compared to $87 million and $173 million in the second quarter and first six months of 2025. Results in the second quarter and first six months of 2026 also included $58 million and $(7) million of unrealized investment gains (losses) from White Mountains’s investment in MediaAlpha compared to $31 million and $(6) million in the second quarter and first six months of 2025.

In the second quarter of 2026, WTM Partners closed two new acquisitions. The acquisition of Basesix, a low voltage contracting platform, closed on April 1, 2026. WTM Partners deployed $97 million into Basesix. Enterprise Solutions’s bolt-on acquisition of Hawkeye Electric, a provider of specialty electrical contracting services, closed on May 1, 2026. WTM Partners deployed $35 million into Enterprise Solutions to fund the acquisition of Hawkeye Electric. Beginning in the second quarter of 2026, in conjunction with the acquisitions of Basesix and Hawkeye Electric, WTM Partners has been presented as a separate reportable segment. Prior period amounts have been reclassified to conform to the current period presentation.

In the second quarter of 2026, White Mountains repurchased and retired 91,194 of its common shares for $191

million at an average share price of $2,092.72, or 93% of White Mountains’s June 30, 2026 book value per share. In the first six months of 2026, White Mountains repurchased and retired 103,816 of its common shares for $217 million at an average share price of $2,088.40, or 93% of White Mountains’s June 30, 2026 book value per share. Including these share repurchases as well as recent deployments and operating company distributions, undeployed capital is roughly $0.8 billion.

The Ark/WM Outrigger segment’s combined ratio was 84% and 88% in the second quarter and first six months of 2026 compared to 84% and 90% in the second quarter and first six months of 2025. The Ark/WM Outrigger segment reported gross written premiums of $778 million and $1,868 million, net written premiums of $537 million and $1,128 million and net earned premiums of $376 million and $750 million in the second quarter and first six months of 2026 compared to gross written premiums of $815 million and $1,923 million, net written premiums of $579 million and $1,306 million and net earned premiums of $364 million and $722 million in the second quarter and first six months of 2025. The Ark/WM Outrigger segment reported pre-tax income of $80 million and $89 million in the second quarter and first six months of 2026 compared to $98 million and $144 million in the second quarter and first six months of 2025.

Ark’s combined ratio was 84% and 88% in the second quarter and first six months of 2026 compared to 85% and 90% in the second quarter and first six months of 2025. Ark’s combined ratio in the second quarter and first six months of 2026 included three points and five points of catastrophe losses, driven primarily by losses related to the war in Iran. This compares to minimal catastrophe losses in the second quarter of 2025 and thirteen points of catastrophe losses in the first six months of 2025, driven by losses related to the California wildfires. Ark’s combined ratio included eight points and six points of net favorable prior year development in the second quarter and first six months of 2026, driven by the property and specialty lines of business. This compares to five points and nine points of net favorable prior year development in the second quarter and first six months of 2025, driven by the property, marine & energy and specialty lines of business, partially offset by six points of unfavorable development in the second quarter related to aviation losses from the conflict in Ukraine. Ark has ongoing exposure to the war in Iran, primarily through the specialty and marine & energy lines of business. In the second quarter and first six months of 2026, Ark recorded estimated losses of $17 million and $42 million (net of reinsurance and reinstatement premiums) related to the war.

Ark reported gross written premiums of $778 million and $1,868 million, net written premiums of $538 million and $1,128 million and net earned premiums of $375 million and $747 million in the second quarter and first six months of 2026 compared to gross written premiums of $815 million and $1,923 million, net written premiums of $536 million and $1,226 million and net earned premiums of $357 million and $703 million in the second quarter and first six months of 2025. The decline in gross written premiums in the second quarter of 2026 was driven primarily by softening market conditions in property lines, which was partially offset by growth in specialty lines. The decline in gross written premiums in the first six months of 2026 was driven primarily by a change in the timing of recognition of certain delegated authority business, which had no impact on the timing of recognition of Ark’s earned premiums.

Ark reported pre-tax income of $78 million and $85 million in the second quarter and first six months of 2026 compared to $91 million and $144 million in the second quarter and first six months of 2025. Ark’s results included net realized and unrealized investment gains (losses) of $31 million and $(2) million in the second quarter and first six months of 2026 compared to $51 million and $81 million in the second quarter and first six months of 2025.

Ark reported book value of $1,615 million as of June 30, 2026, an increase of 4% in the second quarter of 2026 and 5% in the first six months of 2026, including dividends. Ark reported tangible book value of $1,736 million as of June 30, 2026, an increase of 6% in the second quarter of 2026 and 7% in the first six months of 2026, including dividends. Ark’s book value includes goodwill and other intangible assets, net of tax, and White Mountains’s contingent consideration liability, which are excluded from Ark’s tangible book value.

WM Outrigger Re’s combined ratio was 25% and 40% in the second quarter and first six months of 2026 compared to 44% and 120% in the second quarter and first six months of 2025. Catastrophe losses in the first six months of 2025 included $19 million of losses related to the California wildfires (net of reinstatement premiums). Ark renewed Outrigger Re Ltd. for the 2026 underwriting year with $70 million of unaffiliated third-party capital. Through June 30, 2026, WM Outrigger Re has generated pre-tax income of $59 million from the 2025 underwriting year, $29 million from the 2024 underwriting year and $76 million from the 2023 underwriting year. In the first six months of 2026, White Mountains received $145 million of distributions from WM Outrigger Re, primarily a return of capital related to its non-renewal for the 2026 underwriting year. On July 23, 2026, White Mountains received an additional distribution of $77 million.

Kudu reported total revenues of $69 million and $132 million, pre-tax income of $57 million and $109 million and adjusted EBITDA of $16 million and $33 million in the second quarter and first six months of 2026 compared to total revenues of $20 million and $84 million, pre-tax income of $11 million and $64 million and adjusted EBITDA of $16 million and $32 million in the second quarter and first six months of 2025. Total revenues, pre-tax income and adjusted EBITDA included $19 million and $40 million of net investment income in the second quarter and first six months of 2026 compared to $19 million and $39 million in the second quarter and first six months of 2025. Total revenues and pre-tax income also included $50 million and $92 million of net realized and unrealized investment gains in the second quarter and first six months of 2026 compared to $1 million and $45 million in the second quarter and first six months of 2025. The increases in net realized and unrealized investment gains in the second quarter and first six months of 2026 were driven by increases in the fair value of Kudu’s participation contracts, primarily due to lower discount rates across the portfolio and step-ups in valuation related to certain sale transactions. The increase for the first six months of 2026 was also due to growth in assets under management at several managers.

Kudu deployed a total of $36 million, including transaction costs, into two new asset management firms in 2026. As of June 30, 2026, Kudu had deployed a total of $1.2 billion, including transaction costs, into 32 asset and wealth management firms globally, including three that have been exited. As of June 30, 2026, the asset and wealth management firms have combined assets under management of approximately $164 billion, spanning a range of asset classes.

HG Global reported gross written premiums of $11 million and $19 million and earned premiums of $8 million and $15 million in the second quarter and first six months of 2026 compared to gross written premiums of $19 million and $26 million and earned premiums of $7 million and $15 million in the second quarter and first six months of 2025. HG Global’s total par value of policies assumed was $818 million and $1,335 million in the second quarter and first six months of 2026 compared to $931 million and $1,358 million in the second quarter and first six months of 2025. HG Global’s total gross pricing was 135 and 145 basis points in the second quarter and first six months of 2026 compared to 206 and 191 basis points in the second quarter and first six months of 2025. HG Global reported pre-tax income of $10 million and $21 million in the second quarter and first six months of 2026 compared to $17 million and $42 million in the second quarter and first six months of 2025. HG Global’s results included net realized and unrealized investment gains (losses) of $(2) million and $(7) million in the second quarter and first six months of 2026 compared to $3 million and $13 million in the second quarter and first six months of 2025, driven by movements in interest rates.

The fair value of the BAM Surplus Notes was $353 million as of June 30, 2026 compared to $346 million as of March 31, 2026. The increase was driven by $7 million of accrued interest. On July 28, 2026, HG Global received a cash payment of principal and interest on the BAM Surplus Notes of $8 million.

On May 14, 2026, HG Global refinanced its senior debt facility, upsizing the facility to $200 million and lowering the interest rate to a fixed rate of 7.4%. In turn, on May 26, 2026, HG Global paid a $93 million cash dividend to shareholders, of which $90 million was paid to White Mountains. In connection with the extinguishment of its prior senior debt facility, HG Global recognized a $4 million loss within general and administrative expenses.

For the second quarter and first six months of 2026, HG Global grew its book value attributable to White Mountains by 1% and 3%, including the $90 million dividend paid to White Mountains.

Distinguished reported managed premiums of $189 million and $321 million, commission and fee revenues of $57 million and $96 million, pre-tax loss of $11 million and $28 million and ScaleCo adjusted EBITDA of $12 million and $17 million for the second quarter and first six months of 2026. Distinguished’s managed premiums increased 13% in the second quarter of 2026 compared to the second quarter of 2025 and 10% in the first six months of 2026 compared to the first six months of 2025. These figures include periods prior to White Mountains’s ownership of Distinguished, which White Mountains believes is useful in understanding Distinguished’s performance.

WTM Partners reported total revenues of $93 million and $137 million, pre-tax income of $4 million and $2 million and adjusted EBITDA of $9 million and $11 million in the second quarter and first six months of 2026 compared to total revenues of $43 million and $43 million, pre-tax income (loss) of $1 million and $(2) million and adjusted EBITDA of $3 million and $2 million in the second quarter and first six months of 2025.

As of June 30, 2026, White Mountains owned 17.9 million shares of MediaAlpha, representing a 29% basic ownership interest based on the total class A and class B common shares outstanding. As of June 30, 2026, MediaAlpha’s share price was $12.57 per share, which increased from $9.30 per share as of March 31, 2026. The carrying value of White Mountains’s investment in MediaAlpha was $225 million as of June 30, 2026 compared to $166 million as of March 31, 2026. At White Mountains’s June 30, 2026 level of ownership, each $1.00 per share increase or decrease in the share price of MediaAlpha will result in an approximate $7.50 per share increase or decrease in White Mountains’s book value per share.

On July 1, 2026, White Mountains received a distribution of $26 million from the Bamboo SPV.

White Mountains’s total consolidated portfolio return on invested assets was 3.5% in the second quarter of 2026, which included $58 million of unrealized investment gains from White Mountains’s investment in MediaAlpha. Excluding MediaAlpha, the total consolidated portfolio return on invested assets was 2.8% in the second quarter of 2026. Excluding MediaAlpha, investment results were driven primarily by net realized and unrealized investment gains from other long-term investments, net unrealized gains from common equity securities and net investment income from the other long-term investments and fixed income portfolios. White Mountains’s total consolidated portfolio return on invested assets was 2.7% in the second quarter of 2025, which included $31 million of unrealized investment gains from White Mountains’s investment in MediaAlpha. Excluding MediaAlpha, the total consolidated portfolio return on invested assets was 2.3% in the second quarter of 2025. Excluding MediaAlpha, investment results were 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 3.7% in the first six months of 2026, which included $7 million of unrealized investment losses from White Mountains’s investment in MediaAlpha. Excluding MediaAlpha, the total consolidated portfolio return on invested assets was 3.8% in the first six months of 2026. Excluding MediaAlpha, investment results were driven primarily by net unrealized investment gains from other long-term investments and net investment income from the other long-term investments and fixed income portfolios. White Mountains’s total consolidated portfolio return on invested assets was 4.5% in the first six months of 2025, which included $6 million of unrealized investment losses from White Mountains’s investment in MediaAlpha. Excluding MediaAlpha, the total consolidated portfolio return on invested assets was 4.7% in the first six months of 2025. Excluding MediaAlpha, investment results were driven primarily by net investment income and net unrealized investment gains from the other long-term investments and fixed income portfolios.

Book Value Per Share

The following table presents White Mountains’s book value per share as of June 30, 2026, March 31, 2026, December 31, 2025 and June 30, 2025:

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 June 30, 2026, March 31, 2026, December 31, 2025 and June 30, 2025:

(1) The relative fair values of goodwill and other intangible assets recognized in connection with the acquisitions of Basesix and Hawkeye Electric had not yet been finalized. See Note 2 — “Significant Transactions.”

(2) See Note 4 — “Goodwill and Other Intangible Assets” 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 six months ended June 30, 2026 and 2025:

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I. SUMMARY OF OPERATIONS BY SEGMENT

As of June 30, 2026, White Mountains conducted its operations through five reportable segments: (1) Ark/WM Outrigger, (2) Kudu, (3) HG Global, (4) Distinguished and (5) WTM Partners, with its remaining operating businesses, holding companies and other assets included in Other Operations. White Mountains has made its segment determination based on consideration of the following criteria: (i) the nature of the business activities of each of the Company’s subsidiaries and affiliates; (ii) the manner in which the Company’s subsidiaries and affiliates are organized; (iii) the existence of primary managers responsible for specific subsidiaries and affiliates; and (iv) the organization of information provided to the Company’s CODM and the Board of Directors. Significant intercompany transactions among White Mountains’s segments have been eliminated herein. White Mountains’s segment information is presented in Note 14 — “Segment Information” on page 43.

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 six months ended June 30, 2026 and 2025:

58

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Ark/WM Outrigger Results—Three Months Ended June 30, 2026 versus Three Months Ended June 30, 2025

The Ark/WM Outrigger segment’s combined ratio was 84% in both the second quarter of 2026 and 2025. The Ark/WM Outrigger segment reported gross written premiums of $778 million, net written premiums of $537 million and net earned premiums of $376 million in the second quarter of 2026 compared to gross written premiums of $815 million, net written premiums of $579 million and net earned premiums of $364 million in the second quarter of 2025. The Ark/WM Outrigger segment reported pre-tax income of $80 million in the second quarter of 2026 compared to $98 million in the second quarter of 2025.

Ark’s combined ratio was 84% and 85% in the second quarter of 2026 and 2025. Ark’s combined ratio in the second quarter of 2026 included three points of catastrophe losses, driven primarily by losses related to the war in Iran, compared to minimal catastrophe losses in the second quarter of 2025. Ark’s combined ratio in the second quarter of 2026 included eight points of net favorable prior year development, driven by the property and specialty lines of business. This compares to five points of net favorable prior year development in the second quarter of 2025, driven primarily by the property and specialty lines of business, partially offset by six points of unfavorable development related to aviation losses from the conflict in Ukraine.

Ark has ongoing exposure to the war in Iran, primarily through the specialty and marine & energy lines of business. In the second quarter of 2026, Ark recorded estimated losses of $17 million (net of reinsurance and reinstatement premiums) related to the war.

Ark reported gross written premiums of $778 million, net written premiums of $538 million and net earned premiums of $375 million in the second quarter of 2026 compared to gross written premiums of $815 million, net written premiums of $536 million and net earned premiums of $357 million in the second quarter of 2025. The decline in gross written premiums in the second quarter of 2026 was driven primarily by softening market conditions in property lines, which was partially offset by growth in specialty lines.

Ark reported pre-tax income of $78 million in the second quarter of 2026 compared to $91 million in the second quarter of 2025. Ark’s results included net realized and unrealized investment gains of $31 million in the second quarter of 2026, driven primarily by net unrealized investment gains from common equity securities and other long-term investments, compared to net realized and unrealized investment gains of $51 million in the second quarter of 2025, driven primarily by net unrealized investment gains from foreign currency, other long-term investments and common equity securities. Ark’s results also included a $32 million expense related to the increase in fair value of White Mountains’s contingent consideration liability in the second quarter of 2026 compared to $28 million in the second quarter of 2025.

WM Outrigger Re’s combined ratio was 25% in the second quarter of 2026 compared to 44% in the second quarter of 2025. Catastrophe losses were minimal in the second quarter of 2026 and 2025. WM Outrigger Re reported gross written premiums of $0 million and net earned premiums of $1 million in the second quarter of 2026 compared to gross written premiums of $43 million and net earned premiums of $7 million in the second quarter of 2025. WM Outrigger Re reported pre-tax income of $2 million in the second quarter of 2026 compared to $6 million in the second quarter of 2025.

The following tables present the Ark/WM Outrigger segment’s insurance premiums, insurance expenses and insurance ratios for the three months ended June 30, 2026 and 2025:

$ 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 June 30, 2026 and 2025:

$ in Millions

Gross Written Premiums

Gross written premiums decreased 5% to $778 million in the second quarter of 2026 compared to $815 million in the second quarter of 2025, with risk adjusted rate change of -10%. The decline in gross written premiums in the second quarter of 2026 was driven primarily by softening market conditions in property lines, which was partially offset by growth in specialty lines.

The following table presents the Ark/WM Outrigger segment’s gross written premiums by line of business for the three months ended June 30, 2026 and 2025:

Ark/WM Outrigger Results—Six Months Ended June 30, 2026 versus Six Months Ended June 30, 2025

The Ark/WM Outrigger segment’s combined ratio was 88% in the first six months of 2026 compared to 90% in the first six months of 2025. The Ark/WM Outrigger segment reported gross written premiums of $1,868 million, net written premiums of $1,128 million and net earned premiums of $750 million in the first six months of 2026 compared to gross written premiums of $1,923 million, net written premiums of $1,306 million and net earned premiums of $722 million in the first six months of 2025. The Ark/WM Outrigger segment reported pre-tax income of $89 million in the first six months of 2026 compared to $144 million in the first six months of 2025.

Ark’s combined ratio was 88% in the first six months of 2026 compared to 90% in the first six months of 2025. Ark’s combined ratio in the first six months of 2026 included five points of catastrophe losses, driven primarily by losses related to the war in Iran, compared to thirteen points of catastrophe losses in the first six months of 2025, driven by losses related to the California wildfires. Ark’s combined ratio in the first six months of 2026 included six points of net favorable prior year development, driven by the property and specialty lines of business. This compares to nine points of net favorable prior year loss reserve development in the first six months of 2025, driven primarily by the property, marine & energy and specialty lines of business, partially offset by three points of unfavorable development related to aviation losses from the conflict in Ukraine.

Ark has ongoing exposure to the war in Iran, primarily through the specialty and marine & energy lines of business. In the first six months of 2026, Ark recorded estimated losses of $42 million (net of reinsurance and reinstatement premiums) related to the war.

Ark reported gross written premiums of $1,868 million, net written premiums of $1,128 million and net earned premiums of $747 million in the first six months of 2026 compared to gross written premiums of $1,923 million, net written premiums of $1,226 million and net earned premiums of $703 million in the first six months of 2025. The decline in gross written premiums in the first six months of 2026 was driven primarily by a change in the timing of recognition of certain delegated authority business, which had no impact on the timing of recognition of Ark’s earned premiums.

Ark reported pre-tax income of $85 million in the first six months of 2026 compared to $144 million in the first six months of 2025. Ark’s results included net realized and unrealized investment gains (losses) of $(2) million in the first six months of 2026, driven primarily by net unrealized investment losses from fixed maturity investments and foreign currency, partially offset by net unrealized investment gains from other long-term investments, compared to $81 million in the first six months of 2025, driven primarily by net unrealized investment gains from foreign currency, common equity securities and other long-term investments. Ark’s results also included a $42 million expense related to the increase in fair value of White Mountains’s contingent consideration liability in the first six months of 2026 compared to $38 million in the first six months of 2025.

WM Outrigger Re’s combined ratio was 40% in the first six months of 2026 compared to 120% in the first six months of 2025. Catastrophe losses were minimal in the first six months of 2026. Catastrophe losses in the first six 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 $0 million and net earned premiums of $4 million in the first six months of 2026 compared to gross written premiums of $80 million and net earned premiums of $19 million in the first six months of 2025. WM Outrigger Re reported pre-tax income of $4 million in the first six months of 2026, compared to $0 million in the first six months of 2025.

The following tables present the Ark/WM Outrigger segment’s insurance premiums, insurance expenses and insurance ratios for the six months ended June 30, 2026 and 2025:

$ 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 six months ended June 30, 2026 and 2025:

$ in Millions

White Mountains’s capital commitments to WM Outrigger Re were $150 million for the 2025 underwriting year, $130 million for the 2024 underwriting year and $205 million for the 2023 underwriting year. Ark renewed Outrigger Re Ltd. for the 2026 underwriting year with $70 million of unaffiliated third-party capital. Ark’s increased use of traditional quota share reinsurance for 2026 reduced the need for capacity from Outrigger Re Ltd.

Through June 30, 2026, WM Outrigger Re has generated pre-tax income of $59 million from the 2025 underwriting year, $29 million from the 2024 underwriting year and $76 million from the 2023 underwriting year.

In the first six months of 2026, White Mountains received $145 million of distributions from WM Outrigger Re, primarily a return of capital related to its non-renewal for the 2026 underwriting year. On July 23, 2026, White Mountains received an additional distribution of $77 million. As of July 31, 2026, investments of $46 million were held in the collateral trust account to fund WM Outrigger Re’s remaining obligations under the reinsurance agreements with GAIL for the 2024 and 2025 underwriting years. WM Outrigger Re has loss and LAE reserves outstanding of $28 million as of June 30, 2026.

Gross Written Premiums

Ark’s gross written premiums decreased 3% to $1,868 million in the first six months of 2026 compared to $1,923 million in the first six months of 2025, with risk adjusted rate change of -8%. The decline in Ark’s gross written premiums was driven primarily by a change in the timing of recognition of certain delegated authority business. This change had no impact on the timing of recognition of Ark’s earned premiums.

The following table presents the Ark/WM Outrigger segment’s gross written premiums by line of business for the six months ended June 30, 2026 and 2025:

Ark’s Book Value and Tangible Book Value

Ark reported book value of $1,615 million as of June 30, 2026, an increase of 4% in the second quarter of 2026 and 5% in the first six months of 2026, including dividends. Ark reported tangible book value of $1,736 million as of June 30, 2026, an increase of 6% in the second quarter of 2026 and 7% in the first six months of 2026, including dividends. Ark’s book value includes goodwill and other intangible assets, net of tax, and White Mountains’s contingent consideration liability, which are excluded from Ark’s tangible book value. See “NON-GAAP FINANCIAL MEASURES” on page 87.

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 June 30, 2026 and December 31, 2025:

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

(2) See “NON-GAAP FINANCIAL MEASURES” on page 87.

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

(2) See “NON-GAAP FINANCIAL MEASURES” on page 87.

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 a total of $36 million, including transaction costs, into two new asset management firms in 2026. As of June 30, 2026, Kudu had deployed a total of $1.2 billion, including transaction costs, into 32 asset and wealth management firms globally, including three that have been exited. As of June 30, 2026, the asset and wealth management firms have combined assets under management of approximately $164 billion, spanning a range of asset classes, including real estate, real assets, wealth management, hedge funds, private equity and alternative credit strategies. Since inception, Kudu’s capital was deployed at an initial average gross cash yield at inception of approximately 9.3% 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 six months ended June 30, 2026 and 2025:

(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 87.

The following table presents the changes to the fair value of Kudu’s Participation Contracts for the three and six months ended June 30, 2026 and 2025:

(1) As of March 31, 2026, March 31, 2025, December 31, 2025 and December 31, 2024, Kudu’s other long-term investments also include $6.6, $5.8, $6.4 and $5.6 related to a private debt instrument.

(2) Includes contributions to new and existing Participation Contracts.

(3) Includes $3.5 of non-cash contributions to (proceeds from) participation contracts for the three and six months ended June 30, 2026.

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

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

(6) As of June 30, 2025, Kudu’s other long-term investments also include $6.1 related to a private debt instrument.

Kudu Results—Three Months Ended June 30, 2026 versus Three Months Ended June 30, 2025

Kudu reported total revenues of $69 million, pre-tax income of $57 million and adjusted EBITDA of $16 million in the second quarter of 2026 compared to total revenues of $20 million, pre-tax income of $11 million and adjusted EBITDA of $16 million in the second quarter of 2025. Total revenues, pre-tax income and adjusted EBITDA included $19 million of net investment income in both the second quarter of 2026 and 2025. Total revenues and pre-tax income also included $50 million of net realized and unrealized investment gains in the second quarter of 2026 compared to $1 million in the second quarter of 2025. Net realized and unrealized investment gains in the second quarter of 2026 were driven by an increase in the fair value of Kudu’s Participation Contracts, primarily due to lower discount rates across the portfolio and step-ups in valuation related to certain sale transactions. Net realized and unrealized investment gains in the second quarter of 2025 were driven by a modest increase in the fair value of Kudu’s Participation Contracts, primarily due to growth in assets under management at several managers, foreign currency gains resulting from the weakening of the U.S. dollar and a step-up in valuation related to a sale transaction, largely offset by higher discount rates across the portfolio.

Kudu Results—Six Months Ended June 30, 2026 versus Six Months Ended June 30, 2025

Kudu reported total revenues of $132 million, pre-tax income of $109 million and adjusted EBITDA of $33 million in the first six months of 2026 compared to total revenues of $84 million, pre-tax income of $64 million and adjusted EBITDA of $32 million in the first six months of 2025. Total revenues, pre-tax income and adjusted EBITDA included $40 million of net investment income in the first six months of 2026 compared to $39 million in the first six months of 2025. Total revenues and pre-tax income also included $92 million of net realized and unrealized investment gains in the first six months of 2026 compared to $45 million in the first six months of 2025. Net realized and unrealized investment gains in the first six months of 2026 were driven by an increase in the fair value of Kudu’s Participation Contracts, primarily due to growth in assets under management at several managers, lower discount rates across the portfolio and step-ups in valuation related to certain sale transactions. Net realized and unrealized investment gains in the first six months of 2025 were driven by an increase in the fair value of Kudu’s Participation Contracts, primarily due to growth in assets under management at several managers and foreign currency gains resulting from the weakening of the U.S. dollar.

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 tables present the components of pre-tax income (loss) included in the HG Global segment for the three and six months ended June 30, 2026 and 2025:

HG Global Results—Three Months Ended June 30, 2026 versus Three Months Ended June 30, 2025

HG Global reported gross written premiums of $11 million and earned premiums of $8 million in the second quarter of 2026 compared to gross written premiums of $19 million and earned premiums of $7 million in the second quarter of 2025. HG Global reported gross written premiums net of ceding commission paid of $8 million in the second quarter of 2026 compared to $13 million in the second quarter of 2025. HG Global’s total par value of policies assumed, which represents its first-loss exposure on policies assumed from BAM, was $818 million in the second quarter of 2026, of which $741 million was in the primary market and $77 million was in the secondary market. This compares to $931 million in the second quarter of 2025, of which $840 million was in the primary market and $90 million was in the secondary market. The decline in primary and secondary market par assumed was driven by tighter municipal bond spreads, leading to lower demand for municipal bond insurance.

HG Global’s total gross pricing was 135 basis points in the second quarter of 2026, compared to 206 basis points in the second quarter of 2025. Pricing in the primary market decreased to 120 basis points in the second quarter of 2026 compared to 199 basis points in the second quarter of 2025, due to tighter municipal bond spreads and fewer large, high-priced issuances insured by BAM in the second quarter of 2026. Pricing in the secondary market, which is more transaction specific than pricing in the primary market, was 274 basis points in the second quarter of 2026 compared to 277 basis points in the second quarter of 2025. Total pricing net of ceding commission paid decreased to 95 basis points in the second quarter of 2026 compared to 144 basis points in the second quarter of 2025.

The following table presents HG Global’s par value assumed, reinsurance premiums and pricing for the three months ended June 30, 2026 and 2025:

$ 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 of $10 million in the second quarter of 2026 compared to $17 million in the second quarter of 2025. HG Global’s results in the second quarter of 2026 included net realized and unrealized investment gains (losses) on its fixed income portfolio of $(2) million compared to $3 million in the second quarter of 2025, driven by the movement of interest rates in each period. HG Global’s results included interest income on the BAM Surplus Notes of $7 million in the second quarter of 2026 compared to $8 million in the second quarter of 2025.

The fair value of the BAM Surplus Notes increased to $353 million as of June 30, 2026 compared to $346 million as of March 31, 2026, resulting from $7 million of accrued interest. During both the second quarter of 2026 and 2025, HG Global did not receive any payments of principal and interest on the BAM Surplus Notes. On July 28, 2026, HG Global received a cash payment of principal and interest on the BAM Surplus Notes of $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 second quarter of 2026, HG Re received a distribution from the Supplemental Trust of $14 million, which consisted of an assignment of accrued interest on the BAM Surplus Notes of $7 million and a cash distribution of $7 million. During the second quarter of 2025, HG Re received a distribution from the Supplemental Trust of $22 million, which

consisted of an assignment of accrued interest on the BAM Surplus Notes of $15 million and a cash distribution of $7 million.

On May 14, 2026, HG Global refinanced its senior debt facility, upsizing the facility to $200 million and lowering the interest rate to a fixed rate of 7.4%. In turn, on May 26, 2026, HG Global paid a $93 million cash dividend to shareholders, of which $90 million was paid to White Mountains. In connection with the extinguishment of its prior senior debt facility, HG Global recognized a $4 million loss within general and administrative expenses.

HG Global Results—Six Months Ended June 30, 2026 versus Six Months Ended June 30, 2025

HG Global reported gross written premiums of $19 million and earned premiums of $15 million in the first six months of 2026 compared to gross written premiums of $26 million and earned premiums of $15 million in the first six months of 2025. Earned premiums included $1 million recognized as a result of refundings in the first six months of 2026 compared to $2 million in the first six months of 2025. HG Global reported gross written premiums net of ceding commission paid of $14 million in the first six months of 2026 compared to $18 million in the first six months of 2025. HG Global’s total par value of policies assumed, which represents its first-loss exposure on policies assumed from BAM, was $1,335 million in the first six months of 2026, of which $1,159 million was in the primary market and $176 million was in the secondary market. This compares to $1,358 million in the first six months of 2025, of which $1,167 million was in the primary market and $191 million was in the secondary market. The decline in secondary market par assumed was driven by tighter municipal bond spreads, leading to lower demand for municipal bond insurance.

HG Global’s total gross pricing was 145 basis points in the first six months of 2026 compared to 191 basis points in the first six months of 2025. Pricing in the primary market decreased to 112 basis points in the first six months of 2026 compared to 176 basis points in the first six months of 2025, due to tighter municipal bond spreads and fewer large, high-priced issuances insured by BAM in the first six months of 2026. Pricing in the secondary market, which is more transaction specific than pricing in the primary market, increased to 358 basis points in the first six months of 2026 compared to 283 basis points in the first six months of 2025. Total pricing net of ceding commission paid decreased to 102 basis points in the first six months of 2026 compared to 133 basis points in the first six months of 2025.

The following table presents HG Global’s par value assumed, reinsurance premiums and pricing for the six months ended June 30, 2026 and 2025:

$ 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 of $21 million in the first six months of 2026 compared to $42 million in the first six months of 2025. HG Global’s results in the first six months of 2026 included net realized and unrealized investment gains (losses) on its fixed income portfolio of $(7) million compared to $13 million in the first six months of 2025, driven by movements in interest rates in each period. HG Global’s results in the first six months of 2026 included interest income on the BAM Surplus Notes of $14 million compared to $15 million in the first six months of 2025.

The fair value of the BAM Surplus Notes increased to $353 million as of June 30, 2026 compared to $339 million as of December 31, 2025, resulting from $14 million of accrued interest. During both the first six months of 2026 and 2025, HG Global did not receive any payments of principal or interest on the BAM Surplus Notes.

During the first six months of 2026, HG Re received a distribution from the Supplemental Trust of $29 million, which consisted of an assignment of accrued interest on the BAM Surplus Notes of $14 million and a cash distribution of $15 million. During the first six months of 2025, HG Re received a distribution from the Supplemental Trust of $22 million, which consisted of an assignment of accrued interest on the BAM Surplus Notes of $15 million and a cash distribution of $7 million.

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 June 30, 2026 and December 31, 2025:

(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.

(3) HG Global’s growth in book value attributable to White Mountains is based on the change in HG Global’s total equity attributable to White Mountains’s common shareholders after intercompany eliminations for the period, including the $90.1 dividend paid to White Mountains on May 26, 2026.

For the second quarter and first six months of 2026, HG Global grew its book value attributable to White Mountains by 1% and 3%, including the $90 million dividend paid to White Mountains.

Distinguished

On September 2, 2025, White Mountains acquired a controlling financial interest in Distinguished. See Note 2 — “Significant Transactions” on page 11. Distinguished is a full-service MGA and program administrator for specialty property and casualty insurance. Distinguished places insurance across a diversified portfolio of programs 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 manages various 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 three and six months ended June 30, 2026:

(1) See “NON-GAAP FINANCIAL MEASURES” on page 87.

Distinguished Results – Three Months Ended June 30, 2026

Distinguished reported commission and fee revenues of $57 million, pre-tax loss of $11 million, and ScaleCo adjusted EBITDA of $12 million in the second quarter of 2026.

Distinguished Results – Six Months Ended June 30, 2026

Distinguished reported commission and fee revenues of $96 million, pre-tax loss of $28 million, and ScaleCo adjusted EBITDA of $17 million in the first six months of 2026.

Managed Premiums and Commission and Fee Revenues

The following table presents the managed premiums, which represent the total premiums placed by Distinguished, and commission and fee revenues by vertical for the three and six months ended June 30, 2026:

Distinguished’s managed premiums increased 13% in the second quarter of 2026 compared to the second quarter of 2025 and 10% in the first six months of 2026 compared to the first six months of 2025. Distinguished had strong growth in the environmental and urban real estate programs, partially offset by a decline in the umbrella program. As of June 30, 2026, on a trailing 12 months basis, Distinguished reported total managed premiums of $598 million, which increased 4% quarter-over-quarter. These figures include periods prior to White Mountains’s ownership of Distinguished, which White Mountains believes is useful in understanding Distinguished’s performance.

WTM Partners

WTM Partners acquires and manages businesses on behalf of White Mountains in non-financial services sectors including essential services, light industrial and specialty consumer. In the second quarter of 2026, WTM Partners closed two new acquisitions. The acquisition of Basesix, a low voltage contracting platform, closed on April 1, 2026. WTM Partners deployed $97 million into Basesix. Enterprise Solutions’s bolt-on acquisition of Hawkeye Electric, a provider of specialty electrical contracting services, closed on May 1, 2026. WTM Partners deployed $35 million into Enterprise Solutions to fund the acquisition of Hawkeye Electric. As of June 30, 2026, WTM Partners has deployed roughly $200 million of equity capital. See Note 2 — “Significant Transactions.”

Beginning in the second quarter of 2026, in conjunction with the acquisitions of Basesix and Hawkeye Electric, WTM Partners is presented as a separate reportable segment. Prior period amounts have been reclassified to conform to the current period presentation.

The following table presents the components of GAAP net income (loss), EBITDA and adjusted EBITDA included in the WTM Partners segment for the three and six months ended June 30, 2026 and 2025. These figures include results for periods subsequent to the acquisitions of Enterprise Solutions on April 1, 2025, Basesix on April 1, 2026 and Hawkeye Electric on May 1, 2026.

(1) See “NON-GAAP FINANCIAL MEASURES” on page 87.

WTM Partners Results—Three Months Ended June 30, 2026 versus Three Months Ended June 30, 2025

WTM Partners reported total revenues of $93 million, pre-tax income of $4 million and adjusted EBITDA of $9 million in the second quarter of 2026 compared to total revenues of $43 million, pre-tax income of $1 million and adjusted EBITDA of $3 million in the second quarter of 2025. The increases were driven by solid organic growth at Enterprise Solutions and the acquisitions of Basesix and Hawkeye Electric in the second quarter of 2026.

WTM Partners Results—Six Months Ended June 30, 2026 versus Six Months Ended June 30, 2025

WTM Partners reported total revenues of $137 million, pre-tax income of $2 million and adjusted EBITDA of $11 million in the first six months of 2026 compared to total revenues of $43 million, pre-tax loss of $2 million and adjusted EBITDA of $2 million in the first six months of 2025. The increases were driven by solid organic growth at Enterprise Solutions and the acquisitions of Basesix and Hawkeye Electric in the second quarter of 2026.

Other Operations

The following table presents the components of pre-tax income (loss) included in White Mountains’s Other Operations for the three and six months ended June 30, 2026 and 2025:

(1) Other Operations’s earned insurance premiums and commission and fee revenues are included in other revenues in the consolidated statement of operations.

(2) Other Operations’s loss and LAE, insurance acquisition expenses and amortization of other intangible assets are included in general and administrative expenses in the consolidated statement of operations.

Other Operations Results—Three Months Ended June 30, 2026 versus Three Months Ended June 30, 2025

White Mountains’s Other Operations reported pre-tax income of $115 million in the second quarter of 2026 compared to $35 million in the second quarter of 2025. White Mountains’s Other Operations reported net realized and unrealized investment gains of $72 million in the second quarter of 2026 compared to $32 million in the second quarter of 2025. The increase in net realized and unrealized investment gains was driven primarily by net unrealized investment gains from other-long term investments and common equity securities. White Mountains’s Other Operations reported unrealized investment gains from its investment in MediaAlpha of $58 million in the second quarter of 2026 compared to $31 million in the second quarter of 2025. White Mountains’s Other Operations reported net investment income of $16 million in the second quarter of 2026 compared to $9 million in the second quarter of 2025. See Summary of Investment Results on page 78.

White Mountains’s Other Operations reported general and administrative expenses of $41 million in the second quarter of 2026 compared to $46 million in the second quarter of 2025. Other Operations general and administrative expenses in the second quarter of 2026 included $20 million of parent company compensation and benefits compared to $21 million in the second quarter of 2025.

Share Repurchases

In the second quarter of 2026, White Mountains repurchased and retired 91,194 of its common shares for $191 million at an average share price of $2,092.72, or 93% of White Mountains’s June 30, 2026 book value per share.

Other Operations Results—Six Months Ended June 30, 2026 versus Six Months Ended June 30, 2025

White Mountains’s Other Operations reported pre-tax income (loss) of $38 million in the first six months of 2026 compared to $(21) million in the first six months of 2025. White Mountains’s Other Operations reported net realized and unrealized investment gains of $79 million in the first six months of 2026 compared to $35 million in the first six months of 2025. The increase in net realized and unrealized investment gains was driven primarily by net unrealized gains on other-long term investments. White Mountains’s Other Operations reported unrealized investment losses from its investment in MediaAlpha of $7 million in the first six months of 2026 compared to $6 million in the first six months of 2025. White Mountains’s Other Operations reported net investment income of $29 million in the first six months of 2026 compared to $18 million in the first six months of 2025. See Summary of Investment Results on page 78.

White Mountains’s Other Operations reported general and administrative expenses of $86 million in the first six months of 2026 compared to $78 million in the first six months of 2025. Other Operations general and administrative expenses in the first six months of 2026 included $47 million for parent company compensation and benefits compared to $37 million in the first six months of 2025. The increase in incentive compensation costs was driven primarily by an increase in White Mountains’s share price.

Share Repurchases

In the first six months of 2026, White Mountains repurchased and retired 103,816 of its common shares for $217 million at an average share price of $2,088.40, or 93% of White Mountains’s June 30, 2026 book value per share.

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 December 5, 2025, White Mountains no longer consolidates Bamboo. Through December 5, 2025, White Mountains’s consolidated financial statements included Bamboo’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 six months ended June 30, 2026 and 2025:

(1) See “NON-GAAP FINANCIAL MEASURES” on page 87.

Investment Returns—Three and Six Months Ended June 30, 2026 versus Three and Six Months Ended June 30, 2025

White Mountains’s total consolidated portfolio return on invested assets was 3.5% in the second quarter of 2026, which included $58 million of unrealized investment gains from White Mountains’s investment in MediaAlpha. Excluding MediaAlpha, the total consolidated portfolio return on invested assets was 2.8% in the second quarter of 2026. Excluding MediaAlpha, investment results were driven primarily by net realized and unrealized investment gains from other long-term investments, net unrealized investment gains from common equity securities and net investment income from the other long-term investments and fixed income portfolios. White Mountains’s total consolidated portfolio return on invested assets was 2.7% in the second quarter of 2025, which included $31 million of unrealized investment gains from White Mountains’s investment in MediaAlpha. Excluding MediaAlpha, the total consolidated portfolio return on invested assets was 2.3% in the second quarter of 2025. Excluding MediaAlpha, investment results were 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 3.7% in the first six months of 2026, which included $7 million of unrealized investment losses from White Mountains’s investment in MediaAlpha. Excluding MediaAlpha, the total consolidated portfolio return on invested assets was 3.8% in the first six months of 2026. Excluding MediaAlpha, investment results were driven primarily by net unrealized investment gains from other long-term investments and net investment income from the other long-term investments and fixed income portfolios. White Mountains’s total consolidated portfolio return on invested assets was 4.5% in the first six months of 2025, which included $6 million of unrealized investment losses from White Mountains’s investment in MediaAlpha. Excluding MediaAlpha, the total consolidated portfolio return on invested assets was 4.7% in the first six months of 2025. Excluding MediaAlpha, investment results were driven primarily by net investment income and net unrealized investment gains from the other long-term investments and fixed income portfolios.

Fixed Income Results

White Mountains’s fixed income portfolio, including short-term investments, totaled $4.0 billion and $4.7 billion as of June 30, 2026 and December 31, 2025, which represented 49% and 56% of total invested assets for each period. The duration of White Mountains’s fixed income portfolio, including short-term investments, was 2.1 years and 1.5 years as of June 30, 2026 and December 31, 2025. The change in the fair value and duration of the fixed income portfolio was driven primarily by the sale of short-term investments to fund new capital deployments, share repurchases and the purchase of common equity ETFs. 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 0.9% in the second quarter of 2026 compared to 1.5% in the second quarter of 2025, outperforming and in line with the Bloomberg Intermediate U.S. Aggregate Index returns of 0.5% and 1.5% for the comparable periods. Results in the second quarter of 2026 were driven primarily by net investment income, partially offset by net unrealized investment losses due to the impact of the increase in interest rates on White Mountains’s short duration fixed income portfolio. Results in the second quarter of 2025 were driven primarily by net investment income and net unrealized investment gains due to the impact of the decline in interest rates on White Mountains’s short duration fixed income portfolio.

White Mountains’s fixed income portfolio returned 1.4% in the first six months of 2026 compared to 3.3% in the first six months of 2025, outperforming and underperforming the Bloomberg Intermediate U.S. Aggregate Index returns of 0.6% and 4.2% for the comparable periods. Results in the first six months of 2026 were driven primarily by net investment income, partially offset by net unrealized investment losses due to the impact of the increase in interest rates on White Mountains’s short duration fixed income portfolio. Results in the first six months of 2025 were driven primarily by net investment income and net unrealized investment gains due to the impact 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 $4.1 billion and $3.7 billion as of June 30, 2026 and December 31, 2025, which represented 51% and 44% of total invested assets for each period. The change in fair value was driven primarily by increased exposure to other long-term investments and common equity securities, principally due to new unconsolidated entities, an increase in the fair value of Kudu’s Participation Contracts and the purchase of common equity ETFs. See Note 3 — “Investment Securities.”

White Mountains’s portfolio of common equity securities, its investment in MediaAlpha and other long-term investments returned 6.1% in the second quarter of 2026, which included $58 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 4.9% in the second quarter of 2026. White Mountains’s portfolio of common equity securities, its investment in MediaAlpha and other long-term investments returned 4.2% in the second quarter of 2025, which included $31 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 3.4% in the second quarter of 2025.

White Mountains’s portfolio of common equity securities, its investment in MediaAlpha and other long-term investments returned 5.9% in the first six months of 2026, which included $7 million of unrealized investment losses from White Mountains’s investment in MediaAlpha. White Mountains’s portfolio of common equity securities and other long-term investments returned 6.5% in the first six months of 2026. White Mountains’s portfolio of common equity securities, its investment in MediaAlpha and other long-term investments returned 5.9% in the first six months of 2025, which included $6 million of unrealized investment losses from White Mountains’s investment in MediaAlpha. White Mountains’s portfolio of common equity securities and other long-term investments returned 6.6% in the first six months of 2025.

White Mountains’s portfolio of common equity securities generally consists of international listed equity funds, primarily held at Ark, and passive common equity ETFs. White Mountains’s common equity 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 was $577 million and $483 million as of June 30, 2026 and December 31, 2025. The increase in common equity securities was driven in part by the reallocation of a portion of the sale proceeds from the Bamboo Transaction.

White Mountains’s portfolio of common equity securities returned 8.0% in the second quarter of 2026 compared to 4.5% in the second quarter of 2025, underperforming the S&P 500 Index returns of 15.2% and 10.9% for the comparable periods. White Mountains’s portfolio of common equity securities returned 3.2% in the first six months of 2026 compared to 6.4% in the first six months of 2025, underperforming and outperforming the S&P 500 Index returns of 10.2% and 6.2% for the comparable periods. The underperformance and outperformance 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, the Bamboo SPV, the BroadStreet SPV, PassportCard/DavidShield and Bishop Street, as well as private equity funds and hedge funds, a bank loan fund and Lloyd’s trust deposits. White Mountains’s portfolio of other long-term investments totaled $3.3 billion and $3.0 billion as of June 30, 2026 and December 31, 2025.

White Mountains’s portfolio of other long-term investments returned 4.3% in the second quarter of 2026 compared to 3.0% in the second quarter of 2025. Investment returns for the second quarter of 2026 were driven primarily by net investment income and net realized and unrealized investment gains from Kudu’s Participation Contracts, as well as net unrealized investment gains from certain unconsolidated entities. Investment returns for the second quarter of 2025 were driven primarily by net investment income from Kudu’s Participation Contracts and net realized and unrealized investment gains from certain unconsolidated entities, private equity funds and hedge funds, as well as unrealized gains from foreign currency.

White Mountains’s portfolio of other long-term investments returned 7.1% in the first six months of 2026 compared to 6.4% in the first six months of 2025. Investment returns for the first six months of 2026 were driven primarily by net investment income and net realized and unrealized investment gains from Kudu’s Participation Contracts, as well as net unrealized investment gains from certain unconsolidated entities. Investment returns for the first six months of 2025 were driven primarily by net investment income and net realized and unrealized investment gains from Kudu’s Participation Contracts, as well as net realized and unrealized investment gains from certain unconsolidated entities, private equity funds and hedge funds.

Foreign Currency Exposure

As of June 30, 2026, White Mountains had foreign currency exposure on $455 million of net assets, primarily related to Ark/WM Outrigger’s non-U.S. contracts, Kudu’s non-U.S. Participation Contracts and a non-U.S. Other Operating Business.

The following table presents the fair value of White Mountains’s foreign denominated net assets (liabilities) by segment as of June 30, 2026:

$ in Millions Currency

III. Income Taxes

As of June 30, 2026, the primary jurisdictions in which the Company’s subsidiaries and branches operated and were subject to tax include the United States, the United Kingdom, Luxembourg and Israel.

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 that 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 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. As of June 30, 2026, White Mountains does not expect that it will be subject to a top-up tax for the year ending December 31, 2026.

On July 11, 2023, the United Kingdom enacted conforming Pillar Two legislation including the IIR and QDMTT, which became effective for fiscal years beginning on or after December 31, 2023. On March 20, 2025, the United Kingdom 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 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 December 20, 2023, Luxembourg enacted conforming Pillar Two legislation including the IIR and QDMTT, which became effective for fiscal years beginning on or after December 31, 2023, and the UTPR, which became effective for fiscal years beginning on or after December 31, 2024. The Luxembourg Pillar Two legislation defers 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 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 December 30, 2025, Israel enacted conforming Pillar Two legislation that adopts a QDMTT, which became effective for fiscal years beginning on or after January 1, 2026.

On December 27, 2023, Bermuda enacted a 15% corporate income tax that became effective on January 1, 2025. The Bermuda tax 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 Pillar Two IIR 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 tax legislation also provides for an optional economic transition adjustment that can decrease or increase future years’ taxable income. Under GAAP, this economic transition adjustment was required to be recorded as a deferred tax asset or liability as of December 31, 2023 if a company intended to apply the adjustment to compute its taxable income. Accordingly, White Mountains recognized a net deferred tax benefit of $68 million in 2023, of which $51 million was recognized at Ark and $17 million was recognized at HG Global. As of July 1, 2024, White Mountains no longer consolidates BAM. As a result of the deconsolidation, the BAM Surplus Notes are recorded at fair value, which resulted in the reversal of a $5 million deferred tax liability related to the economic transition adjustment, generating a $5 million deferred tax benefit in 2024. On December 11, 2025, Bermuda enacted legislation that changed the scope of assets and liabilities subject to the economic transition adjustment. This legislation resulted in the reversal of a $5 million deferred tax liability related to the economic transition adjustment, generating a $5 million deferred tax benefit in 2025.

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 recorded under the Bermuda corporate income tax are expected to be within the scope of the January 2025 OECD Administrative Guidance.

On December 17, 2025, Luxembourg enacted legislation that adopts the January 2025 OECD Administrative Guidance. On March 18, 2026, the United Kingdom enacted legislation that adopts the January 2025 OECD Administrative Guidance. Accordingly, in any future year in which the economic transition adjustment deferred tax asset is utilized, White Mountains expects to incur a top-up tax under the Luxembourg and United Kingdom UTPR equal to the amount of the deferred tax expense for that year associated with the economic transition adjustment. Consequently, White Mountains expects to derive no economic benefit from the Bermuda economic transition adjustment and intends to opt out of the economic transition adjustment upon becoming subject to Bermuda corporate income tax. Accordingly, White Mountains recognized a deferred tax expense of $78 million in 2025 to reverse the net deferred tax asset related to the Bermuda economic transition adjustment.

On December 11, 2025, the Bermuda government enacted legislation providing certain incentives for Bermuda-based employment, training, local expenditure and community development. The incentives are based on qualifying expenditures of eligible Bermuda entities and are provided in the form of a refundable tax credit. A Bermuda entity may be eligible for the incentives regardless of whether it is subject to the Bermuda corporate income tax. For the six months ended June 30, 2026, White Mountains recognized a $9 million benefit for the incentives as a reduction to general and administrative expenses.

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 impact on its financial statements.

White Mountains’s income tax expense related to pre-tax income from continuing operations for the three and six months ended June 30, 2026 represented an effective tax rate of 10% and 11%. The effective tax rate was different from the U.S. statutory rate of 21%, driven primarily by full year forecasted income in jurisdictions with lower tax rates than the United States and full valuation allowances on deferred tax assets at certain U.S. operations.

White Mountains’s income tax expense related to pre-tax income from continuing operations for the three and six months ended June 30, 2025 represented an effective tax rate of 7% and 9%. The effective tax rate was different from the U.S. statutory rate of 21%, 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 (i) collections of premiums, commissions and fees and product and services revenues, (ii) net investment income, (iii) proceeds from sales, repayments and maturities of investments, (iv) contributions from holding companies, (v) borrowings from credit facilities and (vi) 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. Collections of premiums, commissions and fees, product and services revenues, 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 $425 million during 2026, which is equal to 25% of its statutory capital and surplus of $1,700 million as of December 31, 2025, subject to meeting all appropriate liquidity and solvency requirements. During the first six months of 2026, GAIL did not pay any dividends to its immediate parent.

During the first six months of 2026, Ark paid a $51 million dividend to shareholders, including $36 million that was paid to White Mountains. As of June 30, 2026, Ark and its intermediate holding companies had $3 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 June 30, 2026, WM Outrigger Re had less than $1 million of net unrestricted cash held outside the collateral trust. As of June 30, 2026, WM Outrigger Re had $91 million of statutory capital and surplus and $123 million of assets held in the collateral trusts pursuant to the reinsurance agreement with GAIL. During the first six months of 2026, White Mountains received $145 million of distributions from WM Outrigger Re. On July 23, 2026, White Mountains received an additional distribution of $77 million.

Kudu

During the first six months of 2026, Kudu distributed $9 million to unitholders, substantially all of which was paid to White Mountains. As of June 30, 2026, Kudu had $106 million of net unrestricted cash and short-term investments.

HG Global

As of June 30, 2026, 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 June 30, 2026, HG Global has accrued $485 million of dividends payable to holders of its preferred shares, $471 million of which is payable to White Mountains and is eliminated in consolidation. As of June 30, 2026, HG Global and its subsidiaries had $2 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 June 30, 2026, HG Re had $7 million of net unrestricted cash and short-term investments. As of June 30, 2026, HG Re had $193 million of accrued interest on the BAM Surplus Notes held outside the Collateral Trusts. As of June 30, 2026, HG Re had $753 million of statutory capital and surplus and $1,014 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 first six months of 2026, HG Global did not receive any payments of principal and interest on the BAM Surplus Notes. During the first six months of 2026, HG Re received a distribution from the Supplemental Trust of $29 million, which consisted of an assignment of accrued interest on the BAM Surplus Notes of $14 million and a cash distribution of $15 million. See Note 10 — “Municipal Bond Guarantee Reinsurance.”

On May 14, 2026, HG Global refinanced its senior debt facility under a private placement transaction. In turn, on May 26, 2026, HG Global paid a $93 million cash dividend to shareholders, of which $90 million was paid to White Mountains.

On July 28, 2026, HG Global received a cash payment of principal and interest on the BAM Surplus Notes of $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.

Distinguished

During the first six months of 2026, Distinguished did not make any distributions to its unitholders. As of June 30, 2026, Distinguished had $12 million of net unrestricted cash and short-term investments.

WTM Partners

During the first six months of 2026, WTM Partners distributed $3 million to unitholders, of which $2 million was paid to White Mountains. As of June 30, 2026, WTM Partners had $7 million of net unrestricted cash and short-term investments.

Other Operations

During the first six months of 2026, White Mountains paid a $2 million common share dividend. As of June 30, 2026, the Company and its intermediate holding companies had $516 million of net unrestricted cash, short-term investments and fixed maturity investments, $225 million of MediaAlpha common stock, $169 million of common equity securities and $332 million of private equity and hedge funds, ILS funds and certain unconsolidated entities.

On July 1, 2026, White Mountains received a distribution of $26 million from the Bamboo SPV, of which $21 million was a return of capital and $5 million was a dividend.

Financing

The following table presents White Mountains’s capital structure as of June 30, 2026 and December 31, 2025:

$ in Millions

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

(2) Net of unamortized issuance costs and original issue discount.

The Company has a senior unsecured revolving credit facility of up to $250 million that matures on July 16, 2028 (the “WTM Credit Facility”). As of June 30, 2026, the WTM Credit Facility was undrawn.

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 the existing ratings for one or more of White Mountains’s subsidiaries may be lowered in the future, which could result in higher borrowing costs and impact White Mountains’s ability to access the capital markets.

Covenant Compliance

As of June 30, 2026, 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 June 30, 2026, White Mountains may repurchase an additional 170,007 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 authorized by its Board of Directors.

During the first six months of 2026, White Mountains repurchased and retired 103,816 of its common shares for $217 million at an average share price of $2,088, which was approximately 93% of White Mountains’s book value per share as of June 30, 2026. Of the shares White Mountains repurchased in the first six months of 2026, 4,229 were to satisfy employee income tax withholding pursuant to employee benefit plans, which do not reduce the amount available under the Board repurchase authorizations.

During the first six months of 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 108% of White Mountains’s book value per share as of June 30, 2025. All of the shares White Mountains repurchased in the first six months of 2025 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 six months ended June 30, 2026 and 2025 follows:

Cash flows from operations for the six months ended June 30, 2026 and June 30, 2025

Net cash used for operations was $25 million for the first six months of 2026 compared to net cash provided from operations of $137 million for the first six months of 2025. The decrease in cash provided from operations was driven primarily by an increase in cash used for operations at Ark/WM Outrigger Re and Distinguished as well as a decrease in cash as a result of the sale of Bamboo, partially offset by proceeds from a sale transaction at Kudu. As of June 30, 2026, the Company and its intermediate holding companies had $516 million of net unrestricted cash, short-term investments and fixed maturity investments, $225 million of MediaAlpha common stock, $169 million of common equity securities and $332 million of private equity funds, hedge funds, ILS funds and certain unconsolidated entities.

Cash flows from investing and financing activities for the six months ended June 30, 2026

Financing and Other Capital Activities

During the first six months of 2026, the Company declared and paid a $2 million cash dividend to its common shareholders.

During the first six months of 2026, White Mountains repurchased and retired 103,816 of its common shares for $217 million, of which 4,229 were to satisfy employee income tax withholding pursuant to employee benefit plans.

On May 14, 2026, HG Global refinanced the HG Global 2022 Senior Notes under a private placement transaction. In the refinancing, HG Global issued $200 million face value fixed rate secured senior notes with a maturity date of May 14, 2036 and received net proceeds of $197 million. HG Global used $150 million of these proceeds to repay the outstanding principal on the HG Global 2022 Senior Notes.

During the first six months of 2026, Kudu repurchased $19 million of management equity incentives.

During the first six months of 2026, Distinguished repaid $1 million of the Distinguished Credit Facility.

Acquisitions and Dispositions

On April 1, 2026, WTM Partners closed the Basesix Transaction. WTM Partners paid $97 million of cash consideration, which included a post-acquisition capital contribution of $1 million, and Basesix borrowed $20 million in new debt as part of the transaction.

On May 1, 2026, Enterprise Solutions closed the Hawkeye Electric Transaction. Enterprise Solutions paid $67 million of cash consideration, including net debt financing of $26 million. In addition, Hawkeye Electric utilized $6 million of cash on hand as part of the transaction.

Cash flows from investing and financing activities for the six months ended June 30, 2025

Financing and Other Capital Activities

During the first six months of 2025, the Company declared and paid a $3 million cash dividend to its common shareholders.

During the first six months of 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 plans.

During the first six months of 2025, Kudu borrowed $8 million in term loans under the Kudu Credit Facility.

During the first six months of 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 first six months of 2025, Bamboo borrowed $110 million in term loans under the Bamboo Credit Facility.

Acquisitions and Dispositions

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

NON-GAAP FINANCIAL MEASURES

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

Ark’s tangible book value, growth in tangible book value and tangible capital

Ark’s tangible book value, growth in tangible book value and tangible capital are non-GAAP financial measures. Tangible book value is a non-GAAP financial measure derived by adjusting GAAP book value to exclude (i) goodwill and other intangible assets, (ii) the deferred tax liability on other intangible assets and (iii) 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. Growth in tangible book value equals the change in tangible book value plus dividends for the period divided by beginning tangible book value. Ark’s tangible capital is a non-GAAP financial measure derived by adding debt to tangible book value. White Mountains believes that these non-GAAP financial measures are useful to management and investors in evaluating Ark’s enterprise value.

The following table presents the reconciliation of Ark’s GAAP book value to tangible book value and tangible capital:

$ in millions

(1) Amounts are net of deferred tax liabilities related to other intangible assets of $43.9.

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 and (ii) transaction expenses. A description of each item follows:

• Net realized and unrealized investment gains (losses) - Represents net unrealized investment gains and losses recorded on Kudu’s Participation Contracts, which are recorded at fair value under GAAP, and realized investment gains and losses on Kudu’s Participation Contracts sold during the period.
• 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 underlying performance. See page 68 for the reconciliation of Kudu’s GAAP net income (loss) to EBITDA and 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 consolidated GAAP 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 certain other items in GAAP net income (loss) in addition to those items added back to calculate ScaleCo EBITDA. The items relate to (i) non-cash equity-based compensation expense, (ii) restructuring expenses and (iii) legal settlement expenses. A description of each item follows:

• Non-cash equity-based compensation expense - Represents non-cash expenses related to Distinguished’s management compensation that are settled with equity units in Distinguished.
• Restructuring expenses - Represents costs related to Distinguished’s corporate restructuring and capital planning activities.
• Legal settlement expenses - Represents amounts incurred related to legal settlements.

White Mountains believes that these non-GAAP financial measures are useful to management and investors in evaluating Distinguished’s underlying 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 underlying performance of Distinguished’s established programs. See page 74 for the reconciliation of Distinguished’s consolidated GAAP net income (loss) to ScaleCo net income (loss), ScaleCo EBITDA and ScaleCo adjusted EBITDA.

WTM Partners’s EBITDA and adjusted EBITDA

WTM Partners’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) transaction expenses and (ii) restructuring and integration expenses. A description of each item follows:

• Transaction expenses - Represents costs directly related to WTM Partners’s mergers and acquisitions activity, such as external lawyer, banker, consulting and placement agent fees, which are not capitalized and are expensed under GAAP.
• Restructuring and integration expenses - Represents costs related to WTM Partners’s corporate restructuring and mergers and acquisitions integration activities.

White Mountains believes that these non-GAAP financial measures are useful to management and investors in evaluating WTM Partners’s underlying performance. See page 76 for the reconciliation of WTM Partners’s GAAP net income (loss) to EBITDA and 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 six months ended June 30, 2026 and 2025:

CRITICAL ACCOUNTING ESTIMATES

Refer to the Company’s 2025 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 “may,” “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 2025 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 war and war-like actions and 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 2025 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 June 30, 2026. 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 second quarter of 2026 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 2025 Annual Report on Form 10-K.