Detailed narrative
Cycle management in a more competitive market
Management's central message was disciplined cycle management: adding where returns are attractive and declining risks that no longer offer an adequate margin of safety. The overall ex-cat accident-year combined ratio rose 130 bps YoY to 82.3%, consistent with tougher conditions, yet all three segments delivered strong underlying results.
On rate-versus-trend, US casualty is running above trend while short-tail property is under rapid rate decreases, netting to North America rates slightly below trend; international sits at a low-single-digit rate decrease over trend but off high starting margins. Management argued its own business mix keeps margins sustainable near-term.
Insurance segment: flat top line, MCE integration, London strength
Insurance produced $66M of underwriting income against a Q1 2025 hurt by the California wildfires. Gross premiums written grew 2% but net premiums written fell 1.4%, reflecting a profitability-over-volume focus and a shift toward lines with lower net-to-gross retention. The ex-cat accident-year loss ratio improved 70 bps to 56.7%, driven mainly by benign London attritional activity.
Growth remains available in E&S casualty, construction, alternative markets and London, offset by softening large-account and E&S property and short-tail London lines. The other-liability claims-made line grew on higher transaction-liability pricing and M&A activity.
Reinsurance: excellent margins amid property-cat softening
Reinsurance delivered $441M of underwriting income (vs $167M a year earlier) at a 76% combined ratio — the fourth consecutive sub-80% quarter — with an ex-cat accident-year combined ratio of 78.1%, comparable to last year. Gross premiums written fell 2.3% and net fell 6% on rate reductions and increased cedent retention, concentrated in other property, property catastrophe and marine; over a third of the property-cat NPW decline came from lower reinstatement premiums versus the wildfire-affected prior year.
Management runs property cat through 50 separate zones, judging current on-book returns still attractive (high teens) and explicitly walking away from business below threshold.
Mortgage: strong and diversifying, with a large non-GSE deal
Mortgage delivered $221M of underwriting income on $266M of net premiums written; net premiums earned dipped ~$6M QoQ on lower CRT cancellation premiums. USMI new insurance written included a large $2.2B non-GSE transaction that lifted NIW by 15%; ex that deal, PMI market share was roughly unchanged.
The US MI delinquency rate fell to 2.06% on seasonal normalization. The underlying loss ratio ticked up because loans now entering default are from larger, more recent post-COVID vintages — frequency assumptions and per-loan severity are stable, but average loan size is higher.
Capital management and buybacks
Arch repurchased $783M of stock in Q1 (8.3M shares) — roughly 87% of operating income per one analyst — and an additional $311M quarter-to-date, while still growing book value per share 1.7%. The Board raised the repurchase authorization by $3B.
Management stressed there is no structural cap on buybacks beyond regulatory limits and stock liquidity, and that with limited organic growth across all three segments it will return excess capital rather than accumulate it. M&A is possible but must be genuinely additive given Arch's scale.
AI adoption and the MCE systems migration
Arch completed the data and system migration of the acquired middle-market (MCE) business off Allianz systems onto Arch systems in just 18 months, which management cited as a strong AI use case — AI wrote some of the code and, more importantly, ran much of the scenario testing that validated the new platform, accelerating time to market.
Management noted it has invested in AI/machine-learning models in mortgage and P&C for a decade. Real value from the MCE platform (scalable client experience, underwriter tools for risk selection and triage) is framed as more a 2027 story than 2026, following stabilization.
Iran conflict and political-violence losses
Current-year cat losses of $174M (net of reinsurance and reinstatement premiums) stemmed mainly from US winter storms and the Iran conflict, and came in slightly below seasonally adjusted natural-cat expectations. The Iran-related losses are man-made cat in the London specialty book (terror, political violence); nothing is paid yet but real losses are recognized as a first stab, with more expected in Q2.
Management sized the industry political-violence loss at roughly $3B and estimated premium for the impacted lines at about $2B, while declining to break out Arch's insurance-versus-reinsurance share. Rates on exposed lines have spiked, and Arch is writing a bit more, cautiously.
Investment income and tax
Net investment income was $408M ($1.13/share); combined with equity-method fund income the total was $568M ($1.57/share pretax), down from $1.60 last quarter on lower cash yields, lower qualified refundable tax-credit benefits and seasonal compensation payouts. The ~$48B, short-duration, high-quality portfolio remains a material earnings contributor.
Cash flow from operations was $1.2B. Income from operating affiliates rose to $36M from $17M (prior year hit by the wildfires), reflecting a reduced Somers Re stake. The effective tax rate was 14.8%, below the 16–18% guide on a 1.7% discrete benefit📎.