---
schema_version: "secwatch.filing_event.v1"
accession: "0000776867-24-000009"
form_type: "8-K"
ticker: "WTM"
cik: "0000776867"
company_name: "WHITE MOUNTAINS INSURANCE GROUP LTD"
filed_at: "2024-05-09T23:59:59+00:00"
generated_at: "2026-06-02T07:39:58.837707+00:00"
event_type: "earnings"
sentiment: "positive"
materiality_score: 0.75
calibrated_materiality_score: 0.75
confidence: "high"
source: SEC EDGAR
---

# White Mountains Q1 ABVPS up 6% to $1,797; MediaAlpha gain $211M

## Summary
- Comprehensive income $236M vs $180M YoY; driven by $211M MediaAlpha unrealized gains.
- Ark combined ratio 94%; gross written premiums $872M (+8% YoY).
- Bamboo managed premiums $90M (3x YoY); MGA adj. EBITDA $6M.
- BAM insured $3.6B municipal bonds (+24% YoY); gross premiums $22M.
- Kudu adj. EBITDA $14M; trailing 12-month net investment income up 4% QoQ.

## SEC filing metadata
- accession: 0000776867-24-000009
- form_type: 8-K
- ticker: WTM
- cik: 0000776867
- company_name: WHITE MOUNTAINS INSURANCE GROUP LTD
- filed_at: 2024-05-09T23:59:59+00:00
- event_type: earnings
- sentiment: positive
- materiality_score: 0.75
- calibrated_materiality_score: 0.75
- confidence: high
- sec_items: 2.02, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/776867/000077686724000009/0000776867-24-000009-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/776867/000077686724000009/wtm-20240509.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0000776867-24-000009
- JSON: https://secwatch.observer/filing/0000776867-24-000009.json
- Plain text: https://secwatch.observer/filing/0000776867-24-000009.txt

## Key facts
- Earnings Releases
  WHITE MOUNTAINS INSURANCE GROUP LTD reported the three months ended March 31, 2024 results: net income Comprehensive income attributable to common shareholders was $236 million.
  - Period: the three months ended March 31, 2024
  - Net income: Comprehensive income attributable to common shareholders was $236 million
  - Result: reported results
  source text: White Mountains Insurance Group, Ltd. issued a press release announcing its results for the three months ended March 31, 2024.
  evidence_url: https://www.sec.gov/Archives/edgar/data/776867/000077686724000009/0000776867-24-000009-index.htm

This AI-assisted summary is a reading aid. Review the linked SEC EDGAR filing before relying on any specific claim.