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White Mountains Insurance Group, Ltd.

WTMNYSETrackedMarket Data VerifiedFinancialsProperty And Casualty Insurance

Coverage
Coverage universe Identity published; no third-party ESG observation yet.
ESG profile reviewed
Last editorial update to this profile.
Quote
Last verified closeObservation time is shown beside the price.
Methodology
How we rateProvider ratings are shown separately, never blended.

Market overview

USD 2,112.23

Up+USD 7.48 (+0.36%) Day change

Last verified close · As of · USD · Market data via Massive Stock Widgets

The market is closed. This is the last verified closing quote, not an intraday price.

Open
USD 2,115.00
Previous close
USD 2,104.75
Day high
USD 2,139.89
Day low
USD 2,081.01
Volume
21,772
Market cap
USD 5,041,303,552
Price chart · 1 Year
White Mountains Insurance Group, Ltd. 1 Year price chartWhite Mountains Insurance Group, Ltd., nyse:WTM, 1 Year price chart in USD. Start USD 1,836.59, end USD 2,098.96, high USD 2,319.41, low USD 1,650.50, up.
Period1 YearFirst closeUSD 1,836.59Last closeUSD 2,098.96Maximum closeUSD 2,319.41Minimum closeUSD 1,650.50Period change+USD 262.37Period percentage change+14.29%Chart as ofSep 1, 2026, 1:30 PM GMT+0000
View Chart Data
Representative chart points — 24 of 251
Date and time Open High Low Close Volume
USD 1,815.00 USD 1,842.08 USD 1,804.00 USD 1,836.59 23,800
USD 1,670.00 USD 1,670.00 USD 1,648.00 USD 1,650.50 27,600
USD 1,830.13 USD 1,917.38 USD 1,830.13 USD 1,913.20 32,700
USD 1,902.43 USD 1,920.00 USD 1,890.00 USD 1,904.56 27,800
USD 1,931.89 USD 1,943.46 USD 1,900.00 USD 1,900.00 13,600
USD 2,030.96 USD 2,039.79 USD 2,013.29 USD 2,025.55 16,700
USD 2,062.94 USD 2,098.80 USD 2,036.00 USD 2,040.00 19,400
USD 2,008.04 USD 2,056.10 USD 2,003.97 USD 2,047.31 31,200
USD 2,084.99 USD 2,098.89 USD 2,054.87 USD 2,071.97 13,400
USD 2,151.00 USD 2,232.50 USD 2,147.85 USD 2,185.00 22,900
USD 2,197.08 USD 2,228.98 USD 2,185.50 USD 2,223.42 17,200
USD 2,145.19 USD 2,236.70 USD 2,100.00 USD 2,223.46 26,200
USD 2,219.64 USD 2,231.57 USD 2,196.96 USD 2,205.51 13,400
USD 2,307.10 USD 2,307.10 USD 2,266.62 USD 2,301.14 19,800
USD 2,292.20 USD 2,333.00 USD 2,270.05 USD 2,319.41 14,200
USD 2,260.60 USD 2,286.66 USD 2,245.31 USD 2,267.56 16,000
USD 2,141.68 USD 2,162.00 USD 2,099.94 USD 2,109.20 22,400
USD 2,090.39 USD 2,106.05 USD 2,072.01 USD 2,084.31 23,500
USD 1,995.50 USD 2,030.00 USD 1,991.30 USD 2,024.05 17,700
USD 2,075.60 USD 2,098.50 USD 2,057.34 USD 2,073.39 16,700
USD 2,162.60 USD 2,173.75 USD 2,125.84 USD 2,139.73 15,300
USD 2,151.30 USD 2,151.30 USD 2,087.20 USD 2,118.61 19,100
USD 2,137.82 USD 2,145.00 USD 2,121.09 USD 2,137.12 14,300
USD 2,107.85 USD 2,125.76 USD 2,093.43 USD 2,098.96 22,104

Company Profile & Business Model Overview

White Mountains Insurance Group, Ltd., through its subsidiaries, provides insurance services in the United States. The company operates through HG Global/BAM, Ark, NSM, Kudu, and Other Operations segments. The HG Global/BAM segment provides insurance on municipal bonds issued to finance public purposes, such as schools, utilities, and transportation facilities, as well as reinsurance protection services. The Ark segment writes a portfolio of reinsurance and insurance, including property, accident and health, energy, marine, and political risks. The NSM segment operates as a general underwriting agency and program administrator for specialty property and casualty insurance to various sectors, such as specialty transportation, real estate, social services, and pet. The Kudu segment provides capital solutions to boutique asset and wealth managers for generational ownership transfers, management buyouts, acquisitions, growth finances, and legacy partner liquidity. The Other Operations segment offers insurance solutions to travel industry through broker channel; and manages separate accounts and pooled investment vehicles for insurance-linked securities sectors, including catastrophe bonds, collateralized reinsurance investments, and industry loss warranties of third-party clients. White Mountains Insurance Group, Ltd. was incorporated in 1980 and is headquartered in Hamilton, Bermuda.

Sustainability Strengths & Catalysts (Pros)

  • Owner-focused governance: White Mountains states a governance approach of "thinking like owners," reflecting owner-oriented corporate governance practices intended to align management and shareholder interests.
  • Diversified insurance operations: The company operates multiple insurance and reinsurance subsidiaries (including Ark Insurance Holdings and Outrigger Re), which can provide resilience and risk diversification across underwriting portfolios and geographie
  • Public disclosure of operations and filings: White Mountains publishes annual reports and SEC filings (10-K/10-Q) that detail its insurance subsidiaries, risk exposures and financial results, supporting transparency for investors and stakeholders.

Material Risks & Governance Concerns (Cons)

  • Insurance underwriting and reserving risk: As an operator of specialty insurance and reinsurance businesses, White Mountains faces industry-specific ESG-related exposures such as catastrophe risk, climate-driven loss trends and reserving adequacy that can
  • Limited explicit sustainability metrics disclosed publicly: While the company references governance principles, there is limited evidence in readily available materials of comprehensive, standardized sustainability metrics or third-party ESG targets (e.g.

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ESG & Sustainability Rating Breakdown

Synthesized multi-provider rating across Environmental, Social, and Corporate Governance dimensions.

Audited Methodology

Coverage PendingThird-Party ESG Coverage Under Review

Formal published scorecards from MSCI ESG Research and Sustainalytics are not currently available for this ticker. The Impact Investor tracks corporate sustainability disclosures, SEC 10-K filings, and governance releases.

Data integrity and methodology

MSCI and Sustainalytics ratings are shown separately with their own observation dates; they are not blended into one score, and providers can disagree. Market quotes are delayed or last-close values, and every snapshot states its source and observation time. Read the full rating methodology.

FAQ

Frequently Asked Questions

Direct answers on sustainability scores, risk methodologies, and peer rankings.

What is White Mountains Insurance Group, Ltd. (WTM)'s ESG rating and sustainability score?

Formal published scorecards from MSCI and Sustainalytics are under ongoing review for White Mountains Insurance Group, Ltd. (WTM). The Impact Investor tracks corporate sustainability disclosures, SEC 10-K filings, and governance releases.

Is White Mountains Insurance Group, Ltd. considered an ESG leader or laggard in Financials?

Independent benchmark status for White Mountains Insurance Group, Ltd. is evaluated relative to Financials peers once third-party coverage publishes official methodology scores.

What are the main ESG risks and controversies for White Mountains Insurance Group, Ltd.?

Key material risks for White Mountains Insurance Group, Ltd. include: Insurance underwriting and reserving risk: As an operator of specialty insurance and reinsurance businesses, White Mountains faces industry-specific ESG-related exposures such as catastrophe risk, climate-driven loss trends and reserving adequacy that can; Limited explicit sustainability metrics disclosed publicly: While the company references governance principles, there is limited evidence in readily available materials of comprehensive, standardized sustainability metrics or third-party ESG targets (e.g.. Investors should evaluate whether corporate mitigation plans adequately address these vulnerabilities.

How does The Impact Investor evaluate ESG stock profiles?

The Impact Investor presents audited third-party ratings from MSCI and Sustainalytics alongside delayed market data and financial fundamentals. We do not blend ratings into proprietary black-box scores, and ratings are never modified by advertising or affiliate relationships.