White Mountains reports 1% Q3 book value decline due to investment losses, but 3% growth YTD including dividends.

White Mountains Insurance Group's book value per share fell 1% in Q3 2026 due to unrealized investment losses from higher interest rates and a drop in MediaAlpha's share price, offsetting solid operating results. Despite this, the company achieved a 3% increase in book value for the first nine months of 2026, driven by strong performance in its Ark and Kudu segments. MediaAlpha's share price decline caused significant mark-to-market losses, and White Mountains plans to reduce its stake. The company continues to manage capital prudently amid market challenges and expects to release further financial details in its upcoming SEC filing.

White Mountains Insurance Group's stock trades at USD 2,376.30 on Pluang as of Nov 05, 2026 20:11 WIB. The price shows no change in the last day, holding steady at a market cap of $5.67 billion. Investors see a dividend yield of 0.04%, reflecting a stable but low income return amid recent market challenges.