WTM — White Mountains Insurance Group

Bermuda-based insurance holding company. Opportunistic buy-operate-sell model. AGI Score: 4/10. P/TB 1.07. Buybacks -17%. | Analysis date: 2026-03-13

Why are we looking at this?

White Mountains is a Berkshire-lite: a holding company that buys insurance/financial services businesses at attractive prices, operates them, and sells when valuations are rich. Trading near book value (P/B 0.99) with consistent buybacks. Only ~2,500 shares outstanding (ultra-low float). The question: is this a mini-Berkshire that compounds at 10%+ with low risk, or is it an insurance company disguised as a holding company?

$2,195

Stock Price

$5.4B

Market Cap

0.99x

Price / Book

$3.7B

Revenue (FY2025)

$1.2B

Net Income (FY2025)

$550M

Operating Cash Flow

5.1x

Trailing P/E

0.35

Beta

2,467

Shares Outstanding

Stock Price — WTM

1. The Business

White Mountains is a Bermuda-based holding company that makes opportunistic acquisitions in insurance and financial services. Key segments:

Ark (specialty P&C insurance/reinsurance): Specialty property & casualty insurance and reinsurance. This is the core underwriting operation.
HG Global (municipal bond reinsurance): Niche market — reinsures municipal bond insurers. Very low loss ratios, steady income.
Kudu (capital solutions for asset managers): Provides capital to RIAs and asset managers in exchange for revenue-share arrangements. Clever structure — benefits from AUM growth without directly managing money.
Bamboo (P&C insurance distribution): Insurance distribution platform.

Business model: buy-operate-sell when valuations are attractive. Management explicitly targets book value growth per share as the primary metric. 1,648 employees.

2. Financial History (XBRL)

Metric	FY2020	FY2021	FY2022	FY2023	FY2024	FY2025
Revenue	$521M	$945M	$1.2B	$2.2B	$2.2B	$3.7B
Net Income	$663M	-$322M	$712M	$581M	$284M	$1.2B
Operating Cash Flow	-$61M	$39M	$365M	$404M	$587M	$550M
Total Assets	$4.8B	$7.0B	$7.4B	$8.4B	$9.9B	$12.3B
Stockholders' Equity	$3.8B	$3.7B	$3.9B	$4.6B	$5.1B	$6.1B
Goodwill	$526M	$646M	$176M	$169M	$439M	$614M
Intangible Assets	$9M	$176M	$176M	$202M	$281M	$406M
Long-Term Debt	$376M	$693M	$575M	$579M	$576M	$852M
Shares Outstanding	3,058	2,960	2,711	2,669	2,581	2,467

Book Value Per Share Growth

Year	Equity	Shares	BV/Share	Change
2020	$3.8B	3,058	$1,243	—
2021	$3.7B	2,960	$1,250	+0.6%
2022	$3.9B	2,711	$1,439	+15.1%
2023	$4.6B	2,669	$1,724	+19.8%
2024	$5.1B	2,581	$1,976	+14.6%
2025	$6.1B	2,467	$2,473	+25.2%

Book value per share grew from $1,243 to $2,473 in 5 years = 99% total = ~15% CAGR. This is exceptional. Stock price ($2,195) trails book value ($2,473), meaning you're buying at a discount to growing book. The combination of equity growth + buybacks is compounding at a high rate.

3. AGI Impact Assessment (Score: 4/10)

Insurance underwriting, claims processing, and actuarial modeling are areas where AGI provides significant efficiency gains. White Mountains could benefit from better risk selection and lower operating costs. However, the company is a holding company — value depends on portfolio performance, not direct operations.

Specialty insurance (Ark) has some moat from niche underwriting expertise, but commoditized lines face pricing pressure if AGI reduces loss ratios industry-wide
Municipal bond reinsurance (HG Global) is niche with limited AGI impact
Kudu (capital solutions) could actually benefit — AGI makes asset management more efficient, growing AUM and Kudu's revenue-share
Net effect: Neutral with slight upside from operational efficiency. Not a major AGI winner or loser.

4. Working Backwards from 10x

What price gives 10x potential?

Current market cap: $5.4B. For 10x = $54B. WTM would need to become a $54B insurance conglomerate. Possible but would require decades of compounding at 15%+, plus acquisitions.

More realistic path: If BV/share continues growing at 15% CAGR (its 5-year rate) and eventually trades at 1.5x book, in 10 years BV/share = $2,473 × (1.15)^10 = $10,005. At 1.5x = $15,008/share = 6.8x from current. Close to 10x but requires sustained excellence.

10x entry price: ~$220/share. At that price the stock would be at 0.09x book — would require a catastrophic insurance loss event.

Verdict: WTM is a 5-7x candidate over a decade, not a 10x from current price. But it's one of the highest-quality compounders in this batch. The risk-adjusted return profile is excellent: low beta (0.35), consistent book value growth, minimal debt, and smart capital allocation.

5. Floor Price Analysis

Method	Value/Share	vs Current ($2,195)	Assumptions
Tangible Book Value	$2,060	-6%	($6.1B - $614M - $406M) / 2,467 shares
Book Value (reported)	$2,473	+13%	$6.1B / 2,467 shares
Trough BV (insurance loss scenario)	$1,600	-27%	Assumes 30% hit to equity from catastrophic losses
Liquidation (conservative)	$1,800	-18%	80% of book value after wind-down costs

Floor estimate: ~$1,600-1,800/share. Confidence: High. Insurance balance sheets are well-regulated, and WTM has conservative reserves. The holding company structure provides transparency. Downside is bounded by tangible assets and regulated insurance reserves.

6. Initial Assessment

Summary

WTM is a mini-Berkshire compounding book value at ~15% annually with smart buybacks and a disciplined buy-operate-sell model. Trading at 0.99x book, which is roughly fair value. The 5-year track record (99% BV/share growth) is impressive. Low beta (0.35) means this stock barely moves with the market.

Not a 10x candidate from current price, but an excellent 5-7x over a decade if the compounding continues. The risk-adjusted profile is among the best in this batch: low downside (floor ~$1,600), steady compounding, conservative management, minimal AGI disruption risk.

WATCHLIST — buy on dips. Ideal entry would be at or below tangible book (~$2,060). At book value or below, this is one of the higher-conviction long-term compounders available.

Data sources: SEC EDGAR XBRL (CIK 776867), yfinance, 10-K filing. Analysis date: 2026-03-13.