Chubb (CB)

Business Overview

Chubb underwrites better than any of the six insurers profiled on this site, and it is also the largest of them: market capitalisation was roughly $129.8 billion as of 10 June 2026. The franchise spans global commercial specialty, middle-market commercial, and high-net-worth personal lines.

FY2025 combined ratio was 85.7%, well inside the strong-underwriting screen of below 95% and far below the preliminary US industry prints of 92.2% (AM Best) and 92.9% (Verisk). Lower is better here: the ratio is claims plus expenses as a share of premium, so anything under 100% is an underwriting profit. The margin comes from underwriting selection across geographies, not from chasing premium volume for its own sake.

Return on equity was 15.0% on a GAAP net-income basis for FY2025, with core operating ROE of 13.7% in the same release. Book value per share excluding AOCI ended 2025 at $201.31, and that 15.0% return places Chubb squarely in the 12 to 16% sustainable ROE band of the P/BV vs ROE guide.

How the Numbers Read

The combined ratio is the P&C scoreboard: loss ratio plus expense ratio, with investment income sitting outside. Chubb's 85.7% implies an underwriting profit of 14.3 cents on every premium dollar before the investment portfolio contributes. Progressive ran 87.4% in FY2025, Travelers 89.9% and AIG's General Insurance business 90.1%, so Chubb sits about four points clear of the weakest of the four. All four are calendar-year figures, which matters for the next paragraph.

Investment income amplifies the underwriting result. FY2025 net investment income was $6,947 million on an adjusted pre-tax basis ($6,465 million pre-tax). Average book yield on fixed income investments was 5.1%, the highest of the six insurers here. Book yield is what the bonds already owned are earning, so it moves slowly: a rate move changes only the money being reinvested that year.

Part of that 85.7% is not this year's work. Prior-year reserve development, or PYD, was favourable $1,133 million pre-tax in FY2025 ($858 million after-tax), meaning claims from earlier years settled for less than Chubb had set aside, and the difference is released into this year's loss ratio. Against roughly $46 billion of P&C premium earned, that release is worth about two and a half points of the combined ratio. Strip it and the underwriting Chubb actually did in 2025 reads closer to 88%. The reserve development guide makes the wider point: a long run of releases says the company has booked reserves conservatively in the past, not that today's reserves are adequate. US liability lines swung to $7.8 billion of adverse development in calendar 2024 after years of the opposite.

Premiums arrive before claims leave, so float scales with premium volume. Underwriting profit makes that float cheaper than any bank deposit. Chubb's sub-90% combined ratio means the cost of float is deeply negative in underwriting terms, and the 5.1% fixed-income book yield compounds on a growing balance sheet. The float guide walks through why you cannot rank raw yields across filers without reading each label; Chubb's 5.1% is a fixed-income book yield, not an after-tax total portfolio figure.

Valuation Framework

Insurer equity research starts with P/BV on ex-AOCI book against sustainable ROE. At steady state analysts use P/BV ≈ ROE ÷ cost of equity as a sanity check; a 10.0% nominal COE would imply about 1.50× on 15.0% GAAP ROE. A franchise the market trusts to hold combined ratio inside the strong band through cycles commands a multiple above that line.

Cross-check against the screening bands: 12 to 16% sustainable ROE maps to roughly 1.3 to 1.8× P/BV, and a 15.0% GAAP ROE places Chubb mid-band. The distance between a proven underwriting ceiling and a turnaround still earning a sub-8% GAAP return is what separates a mid-band multiple from one down at the floor of the range.

What to Watch in the Financials

Combined ratio versus the 85 to 86% run rate. Any sustained drift toward 90% would still beat the industry, but it would narrow the float advantage that supports the ROE premium.

PYD sign and magnitude. Favourable $1,133 million pre-tax in FY2025 helped the loss ratio. Adverse development on a name with Chubb's history would be a sentiment shock even if the absolute dollars were manageable.

Book yield versus reinvestment. 5.1% fixed-income book yield reflects the portfolio already on the balance sheet. New money rates and credit spread moves flow through with a lag; watch NII growth against average invested assets, not spot Treasury moves alone.

Core operating ROE (13.7%) versus GAAP (15.0%). The gap is the usual noise between operating and reported equity returns. If GAAP ROE falls toward core while the combined ratio stays strong, AOCI or catastrophe load is doing the work, not underwriting.

Key Risks

Large-loss and catastrophe frequency. Industry cat losses added an estimated 7.6 points to the 2025 US P&C combined ratio. Chubb's global commercial book carries natural catastrophe exposure that a single benign year cannot erase from pricing.

Social inflation and liability lines. The $7.8 billion adverse industry PYD in calendar 2024 concentrated in liability. Chubb's favourable FY2025 development does not immunise future accident years from the same trend.

Multiple compression on ROE slip. The multiple prices sustained mid-teens ROE. A year where combined ratio normalises toward 90% without a matching investment-income offset would pressure both GAAP ROE and the multiple.