White Mountains Insurance Group, Ltd. filed a Form 8-K on August 6, 2026, announcing its results for the three and six months ended June 30, 2026, and disclosing 14 non-GAAP financial measures used alongside its GAAP reporting.

Key Highlights

  • Reporting period: Results cover the three and six months ended June 30, 2026.
  • Ark tangible book value: $1,736.4 million at June 30, 2026, up from $1,636.8 million at March 31, 2026, and $1,673.6 million at December 31, 2025, according to the filing.
  • Ark quarter-to-date growth: Tangible book value growth including dividends was 6.1% for the quarter ended June 30, 2026, compared to 0.8% for the prior quarter, the filing states.
  • Ark year-to-date growth: Growth in tangible book value including dividends was 6.8% for the year to date ended June 30, 2026, the filing discloses.
  • Year-to-date dividends declared: Ark declared $50.5 million in dividends for the year to date ended June 30, 2026, per the filing.
  • Non-GAAP measures: The filing identifies 14 non-GAAP financial measures across subsidiaries Ark, Kudu, Distinguished, and WTM Partners, each reconciled to the most comparable GAAP measure.

White Mountains Discloses Q2 2026 Financial Results and Non-GAAP Reconciliations

White Mountains Insurance Group, Ltd., whose common shares are listed on the New York Stock Exchange under the symbol WTM and on the Bermuda Stock Exchange under the symbol WTM.BH, filed a current report on August 6, 2026, attaching a press release as Exhibit 99.1. The press release covers the company's results for the three and six months ended June 30, 2026. The filing is made under Item 2.02, Results of Operations and Financial Condition.

The filing presents a reconciliation table for Ark's book value. Ark's GAAP book value stood at $1,615.0 million at June 30, 2026. After subtracting goodwill and other intangible assets, net of deferred tax liabilities, of $248.6 million, and adding back a contingent consideration liability of $370.0 million, the filing arrives at Ark's tangible book value of $1,736.4 million. The contingent consideration liability, according to the filing, "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 multiple of invested capital return thresholds."

For Kudu, the filing defines EBITDA, adjusted EBITDA, annualized adjusted EBITDA, annualized revenue, and cash revenue yield as non-GAAP measures, with reconciliations located on page 18 of Exhibit 99.1. For Distinguished, three non-GAAP measures are defined under the "ScaleCo" label, which excludes results of the GrowthCo vertical. The filing states that White Mountains "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." Reconciliations for Distinguished appear on page 21 of Exhibit 99.1.

What Was Disclosed

White Mountains Insurance Group filed an 8-K on August 6, 2026, furnishing its Q2 and first-half 2026 results via a press release. The filing identifies 14 non-GAAP measures across four subsidiaries and provides reconciliation tables for Ark's tangible book value and related growth figures.