White Mountains Ark/WM Outrigger sees GWP up to $815m with improved CoR

White Mountains has released the second quarter of 2025 results for its property and casualty re/insurance segment Ark/WM Outrigger, revealing gross written premiums (GWP) of $815 million, with a combined ratio of 84%.

GWP in Q2 2025 increased compared to Q2 2024’s $697 million, while the quarter’s combined ratio significantly improved when compared to the 90% reported in the same period last year.

Ark/WM Outrigger net written premiums also experienced growth in Q2 2025, to $579 million compared to the $503 million seen in Q2 2024. Net earned premiums stood at $364 million in the quarter, compared to the $318 million in Q2 2024.

White Mountains also announced Ark/WM Outrigger’s financial results for the first six months of 2025, reporting GWP of $1,923 million, net written premiums of $1,306 million and net earned premiums of $722 million, all improvements compared to the same period of last year.

Ark’s combined ratio was 85% in Q2 2025 and 90% for H1 2025. Ark’s combined ratio in the first half of the year included 13 points of catastrophe losses, driven by losses related to the January 2025 California wildfires.

In the second quarter and first six months of 2025, Ark’s combined ratio benefited from net favourable prior year development of five and nine points, respectively, primarily driven by the property, marine & energy, and specialty lines of business.

However, these gains were partially offset by six points of unfavourable development in the second quarter, attributed to aviation losses stemming from the conflict in Ukraine.

This compares to two points and one point of net favourable prior year development in the second quarter and first six months of 2024, driven primarily by the property line of business.

Meanwhile, WM Outrigger Re’s combined ratio was 44% and 120% in the Q2 and H1 2025. Catastrophe losses in the first half of 2025 included $19 million of losses related to the California wildfires (net of reinstatement premiums).

Ian Beaton, CEO of Ark, commented: “We enjoyed good results for the first half of 2025. Ark’s combined ratio was 85% for the second quarter and 90% year to date, both better than prior year. Gross written premiums in the quarter were up 17% year-over-year, aided by the addition of new underwriting teams and classes of business.”

Company wide, White Mountains reported book value per share of $1,804 as of June 30, 2025. Comprehensive income (loss) attributable to common shareholders was $124 million and $159 million in Q2 2025.

Manning Rountree, CEO, said: “BVPS was up 3% in the quarter. We had sound results at our operating companies and good investment returns. Ark produced an 85% combined ratio and $815 million of gross written premiums in the quarter, up 17% year-over-year.

“HG Global generated $19 million of gross written premiums, a record second quarter, and grew book value by 2%. Kudu managed flattish results under volatile market conditions. Bamboo had a record quarter, with significant growth in managed premiums and adjusted EBITDA. MediaAlpha’s share price increased 19% in the quarter, producing a $31 million mark-to-market gain.

“Excluding MediaAlpha, our investment portfolio was up 2.3%. In July, we announced our acquisition of Distinguished Programs and closed our transaction with BroadStreet Partners. Including these deployments, undeployed capital now stands at roughly $300 million.”