White Mountains book value falls 1% as MediaAlpha stake drops 28%; deploys $257M into new ventures

Filed May 6, 2026 · Period ending March 31, 2026 · Compared to 10-Q May 7, 2025 · ~2 min read

Key Changes

• high

  Book value per share declined 1% to $2,170 in Q1 2026, reversing prior year's 0.4% gain. MediaAlpha's share price fell 28% ($12.95 to $9.30), driving a $65M unrealized loss that offset solid operating results.

  MD&A: Book Value Performance verify on EDGAR →
• high

  Deployed $257M across three new investments: $125M into Bishop Street MGA platform, $97M into BaseSix electrical systems integrator, and $35M into Hawkeye specialty electrical contractor.

  MD&A: Capital Deployment verify on EDGAR →
• high

  Undeployed capital rose to $800M from $550M despite new deployments, indicating significant cash generation from operating companies and increased dry powder for future investments.

  MD&A: Liquidity verify on EDGAR →