[8-K] White Mountains Insurance Group Ltd. Reports Material Event

Rhea-AI Filing Summary

White Mountains Insurance Group (WTM) filed an 8-K (Item 2.02) to furnish Q2 2025 results released on 7 Aug 2025.

• Bamboo MGA profitability surged: Q2 pre-tax income rose to $15.0 m from $6.0 m YoY; six-month pre-tax income climbed to $25.2 m from $7.3 m.
• Consolidated GAAP figures: Bamboo GAAP pre-tax income reached $16.1 m (vs $6.4 m).
• Investment performance: Total consolidated portfolio return was 2.7 % in Q2 (-0.1 % in Q2 2024) and 4.5 % YTD. Excluding MediaAlpha, returns improved to 2.3 % for Q2 and 4.7 % YTD.
• Equity portfolio: Q2 return of 4.2 %; excluding MediaAlpha 3.4 %.
• Non-GAAP focus: The press release presents 11 non-GAAP metrics for Kudu, Bamboo and portfolio returns, with reconciliations referenced in Exhibit 99.1.

No other material transactions or guidance were disclosed in the filing; the full financial detail resides in the attached press release.

Positive

• Bamboo MGA pre-tax income rose 150 % YoY to $15 m, indicating strong underwriting and fee growth.
• Total consolidated portfolio generated a 2.7 % Q2 return versus –0.1 % a year ago.
• Excluding MediaAlpha, YTD portfolio return improved to 4.7 %, showing resilience of core investments.

Negative

• MediaAlpha holdings reduced Q2 portfolio return by 0.4 pp and equity return by 0.8 pp.
• Extensive use of 11 non-GAAP measures increases complexity and may obscure GAAP comparability.

Insights

Financial Analyst

TL;DR: Strong Bamboo results and positive portfolio returns offset minor MediaAlpha drag.

WTM’s Q2 filing highlights sharp profit expansion at Bamboo, a key growth platform, and solid investment gains. The 150 % YoY jump in Bamboo’s MGA pre-tax income demonstrates operating leverage and validates the MGA model. Portfolio returns rebounded to 2.7 %, reversing last year’s small loss; stripping out MediaAlpha reveals a slightly lower but cleaner 2.3 % figure, indicating underlying asset performance is healthy. Heavy reliance on numerous non-GAAP metrics may warrant investor caution, yet reconciliations are provided. Overall impact is positive given improved profitability and market returns.

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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

August 7, 2025

Date of Report (Date of earliest event reported)

WHITE MOUNTAINS INSURANCE GROUP, LTD.

(Exact name of registrant as specified in its charter)

Bermuda (State or other jurisdiction of  incorporation or organization) 1-8993 (Commission file number) 94-2708455 (I.R.S. Employer Identification No.)

23 South Main Street, Suite 3B, Hanover, New Hampshire 03755

(Address of principal executive offices)

(603) 640-2200

(Registrant’s telephone number, including area code)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Title of each class

Trading Symbol(s)

Name of each exchange on which registered

Common Shares, par value $1.00 per share

WTM

New York Stock Exchange

WTM.BH

Bermuda Stock Exchange

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933(§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).                                     Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.      o

ITEM 2.02. RESULTS OF OPERATIONS AND FINANCIAL CONDITION.

On August 7, 2025, White Mountains Insurance Group, Ltd. issued a press release announcing its results for the three and six months ended June 30, 2025. The press release furnished herewith is attached as Exhibit 99.1 to this Form 8-K.

Certain information included in the press release constitutes non-GAAP financial measures (as defined in Regulation G of the Securities and Exchange Commission). Specifically, there are 11 non-GAAP financial measures: (i) Kudu’s EBITDA, (ii) Kudu’s adjusted EBITDA, (iii) Kudu’s annualized adjusted EBITDA, (iv) Kudu’s annualized revenue, (v) Kudu’s cash revenue yield, (vi) Bamboo’s MGA pre-tax income (loss), (vii) Bamboo’s MGA net income (loss), (viii) Bamboo’s MGA EBITDA, (ix) Bamboo’s MGA adjusted EBITDA, (x) total consolidated portfolio return excluding MediaAlpha and (xi) total equity portfolio return excluding MediaAlpha. These non-GAAP financial measures have been reconciled from their most comparable GAAP financial measures.

Kudu’s EBITDA, adjusted EBITDA, annualized adjusted EBITDA, annualized revenue and cash revenue yield 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 revenue and earnings participation contracts, (ii) non-cash equity-based compensation expense and (iii) transaction expenses. A description of each item follows:

•Net realized and unrealized investment gains (losses) - Represents net unrealized investment gains and losses recorded on Kudu’s revenue and earnings participation contracts, which are recorded at fair value under GAAP, and realized investment gains and losses from participation contracts sold during the period.

•Non-cash equity-based compensation expense - Represents non-cash expenses related to Kudu’s management compensation that are settled with equity units in Kudu.

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

Annualized adjusted EBITDA is a non-GAAP financial measure that (i) annualizes partial year revenues related to Kudu’s revenue and earnings participation contracts acquired during the previous 12-month period and (ii) removes partial year revenues related to revenue and earnings participation contracts sold during the previous 12-month period. Annualized revenue is a non-GAAP financial measure that adds the adjustments for annualized adjusted EBITDA to GAAP net investment income. Cash revenue yield is a non-GAAP financial measure that is derived using annualized revenue as a percentage of total net capital drawn and invested. The most directly comparable GAAP financial measure is net investment income revenue yield, which is derived using GAAP net investment income as a percentage of total net capital drawn and invested.

White Mountains believes that these non-GAAP financial measures are useful to management and investors in evaluating Kudu’s performance. White Mountains also believes that annualized adjusted EBITDA is useful to management and investors in understanding the full earnings profile of Kudu’s business as of the end of any 12-month period. See page 19 of Exhibit 99.1 to this Form 8-K for the reconciliation of Kudu’s GAAP net income (loss) to EBITDA, adjusted EBITDA and annualized adjusted EBITDA, and the reconciliation of Kudu’s GAAP net investment income to annualized revenue.

Bamboo’s MGA pre-tax income (loss), MGA net income (loss), MGA EBITDA and MGA adjusted EBITDA are non-GAAP financial measures. MGA pre-tax income (loss) and MGA net income (loss) are non-GAAP financial measures that exclude the results of the Bamboo captive, which is consolidated under GAAP, from Bamboo’s consolidated GAAP pre-tax income (loss) and net income (loss). The following table presents the reconciliation from Bamboo’s consolidated GAAP pre-tax income (loss) to MGA pre-tax income (loss):

						Three Months Ended June 30,												Six Months Ended June 30,
Millions						2025						2024						2025						2024
Bamboo’s consolidated GAAP pre-tax income (loss)						$	16.1					$	6.4					$	22.4					$	7.3
Remove pre-tax (income) loss, Bamboo captive						(1.1)						(.4)						2.8						—
MGA pre-tax income (loss)						$	15.0					$	6.0					$	25.2					$	7.3

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

•Non-cash equity-based compensation expense - Represents non-cash expenses related to Bamboo’s management compensation that are settled with equity units in Bamboo.

•Software implementation expenses - Represents costs directly related to Bamboo’s implementation of new software.

•Restructuring expenses - Represents costs directly related to Bamboo’s corporate restructuring and capital planning activities.

White Mountains believes that these non-GAAP financial measures are useful to management and investors in evaluating Bamboo’s performance. See page 21 of Exhibit 99.1 to this Form 8-K for the reconciliation of Bamboo’s consolidated GAAP net income (loss) to MGA net income (loss), MGA EBITDA and MGA adjusted EBITDA.

Total consolidated portfolio return excluding MediaAlpha and total equity portfolio return excluding MediaAlpha are non-GAAP financial measures that remove the net investment income and net realized and unrealized investment gains (losses) from White Mountains’s investment in MediaAlpha. White Mountains believes these measures to be useful to management and investors by showing the underlying performance of White Mountains’s investment portfolio and equity portfolio without regard to White Mountains’s investment in MediaAlpha. The following tables present reconciliations from GAAP to the reported percentages:

						Three Months Ended June 30,												Six Months Ended June 30,
						2025						2024						2025						2024
Total consolidated portfolio return						2.7		%				(0.1)		%				4.5		%				4.5		%
Remove MediaAlpha						(0.4)						2.3						0.2						(1.0)
Total consolidated portfolio return excluding MediaAlpha						2.3		%				2.2		%				4.7		%				3.5		%

												Three Months Ended June 30, 2025
Total equity portfolio return																		4.2		%
Remove MediaAlpha																		(0.8)
Total equity portfolio return excluding MediaAlpha																		3.4		%

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ITEM 9.01. FINANCIAL STATEMENTS AND EXHIBITS.

(d) Exhibits

99.1 Press Release of White Mountains Insurance Group, Ltd. dated August 7, 2025, furnished herewith.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized.

WHITE MOUNTAINS INSURANCE GROUP, LTD.

August 7, 2025

By:

/s/   MICHAELA J. HILDRETH            Michaela J. Hildreth       Managing Director and        Chief Accounting Officer

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FAQ

What drove White Mountains (WTM) earnings in Q2 2025?

Bamboo’s MGA unit delivered $15 m pre-tax income, up from $6 m YoY, and investment portfolio gains added 2.7 %.

How did WTM’s investment portfolio perform in Q2 2025?

Total consolidated return was 2.7 %; excluding MediaAlpha the return was 2.3 %.

What impact did MediaAlpha have on WTM’s returns?

MediaAlpha reduced Q2 consolidated return by 0.4 pp and equity return by 0.8 pp.

Which non-GAAP metrics are highlighted in the 8-K?

11 measures including Kudu’s EBITDA and Bamboo’s MGA adjusted EBITDA; reconciliations are in Exhibit 99.1.

What are Bamboo’s year-to-date results?

MGA pre-tax income reached $25.2 m for the six months versus $7.3 m in 2024.