Business Context and Reporting Period
Company: Arch Capital Group Ltd. (ACGL)
Filing Type: Form 10-K (Annual Report)
Reporting Period: Fiscal Year Ended December 31, 2025
Business Overview: Arch Capital is a Bermuda-based global provider of specialty insurance, reinsurance, and mortgage insurance. The company operates through three primary segments: Insurance, Reinsurance, and Mortgage. As of December 31, 2025, the company held approximately $26.9 billion in capital and is a component of the S&P 500 index.
Key Financial Metrics
| Metric | 2025 | 2024 | Change |
|---|---|---|---|
| Net Income Available to Common Shareholders | $4.36 billion | $4.27 billion | +2.0% |
| Net Premiums Written | $16.48 billion | $15.73 billion | +4.7% |
| Net Premiums Earned | $17.07 billion | $15.10 billion | +13.0% |
| Combined Ratio | 82.8% | 82.5% | +0.3 pts |
| Book Value Per Share | $65.11 | $53.11 | +22.6% |
| Operating Return on Average Common Equity | 17.1% | 18.9% | -1.8 pts |
| Total Investable Assets | $47.4 billion | $40.5 billion | +17.0% |
| Loss Reserves (Net) | $24.49 billion | $21.55 billion | +13.6% |
Material Changes vs. Prior Period
- Acquisition Impact: The 2025 results were significantly influenced by the August 1, 2024, acquisition of Allianz's U.S. Middle Market Property & Casualty and U.S. Entertainment businesses ("MCE Acquisition"). This drove a 13.4% increase in Insurance segment net premiums written.
- Underwriting Performance:
- Insurance Segment: Reported $375 million in underwriting income (Combined Ratio: 95.2%). Growth was driven by the MCE Acquisition, though the combined ratio worsened slightly due to higher acquisition expenses.
- Reinsurance Segment: Reported $1.56 billion in underwriting income (Combined Ratio: 80.8%). Performance improved due to favorable prior year reserve development ($322 million) and a lower current year loss ratio (60.8% vs 62.3% in 2024), despite rate pressure in property catastrophe renewals.
- Mortgage Segment: Reported $1.00 billion in underwriting income (Combined Ratio: 14.6%). Net premiums written declined 4.7% due to lower gross premiums and tender offers on mortgage-linked notes. The segment achieved a negative loss ratio (-0.4%) driven by significant favorable prior year development ($235 million).
- Investment Results: Net investment income increased to $1.63 billion (yield of 4.11%). Net realized gains were $464 million, reflecting sales of investments and fair value changes. Total return on investments was 8.52%, slightly underperforming the benchmark of 8.78%.
- Taxation: The effective tax rate increased to 14.7% from 7.7% in 2024. This increase is primarily attributed to the enactment of the Bermuda Corporate Income Tax Act (15% rate) effective January 1, 2025, and the implementation of OECD Pillar II minimum tax rules in various jurisdictions.
Guidance, Outlook, and Risks
Management Outlook: Management expressed "measured optimism" for 2026, noting increased competition in property and casualty businesses. The company remains committed to disciplined underwriting and risk selection. The strong balance sheet provides optionality for capital deployment and returns to shareholders.
Share Repurchases: In 2025, the company repurchased approximately $1.9 billion of common shares. As of December 31, 2025, $1.1 billion remained available under the repurchase program.
Key Risks and Contingencies:
- Catastrophic Events: The company maintains significant exposure to natural catastrophes. As of January 1, 2026, the modeled peak zone catastrophe exposure (Florida Tri-County windstorm) represented a net probable maximum pre-tax loss of $1.9 billion (approx. 25% of tangible equity).
- Regulatory Changes: The company faces evolving regulatory landscapes, including the new Bermuda corporate income tax, OECD Pillar II implementation, and increased scrutiny on climate change disclosures and AI usage in underwriting.
- Reinsurance Counterparty Risk: The company relies on reinsurers to meet obligations. While over 96% of un-rated reinsurance recoverables are collateralized, failure of reinsurers could impact financial results.
- Mortgage Market Sensitivity: The mortgage segment is sensitive to housing market conditions, interest rates, and GSE policies. The company monitors delinquency rates, which rose slightly to 2.17% in 2025.
Investor Verification Checklist
- Tax Impact: Verify the long-term impact of the new 15% Bermuda corporate income tax and OECD Pillar II top-up taxes on future effective tax rates and net income.
- Reserve Adequacy: Review the $24.5 billion in net loss reserves, specifically the sensitivity analysis regarding prior year development and the potential for adverse development in long-tail casualty lines.
- Acquisition Integration: Assess the integration progress and profitability contribution of the MCE Acquisition (Allianz business) in the Insurance segment.
- Catastrophe Exposure: Confirm the company's current modeled probable maximum loss (PML) limits relative to tangible equity, particularly regarding windstorm and earthquake exposures.
- Capital Management: Monitor the $1.1 billion remaining share repurchase authorization and the company's ability to maintain financial strength ratings amidst competitive rate environments.