Hamilton Insurance Group, Ltd.

The following significant items impacted the consolidated results of operations for the three months ended March 31, 2026 and 2025:

Gross premiums written Gross premiums written were $940.1 million and $843.3 million for the three months ended March 31, 2026 and 2025, respectively. The increase in gross premiums written was primarily driven by our casualty reinsurance and insurance classes and specialty insurance classes as a result of growth in both new and existing business, partially offset by a decrease in our property reinsurance classes primarily as a result of lower reinstatement premiums for the three months ended March 31, 2026.

Underwriting results The combined ratio was 89.8% and 111.6% for the three months ended March 31, 2026 and 2025, respectively. The decrease was primarily driven by a decrease in the catastrophe loss ratio and other underwriting expense ratio, partially offset by an increase in the attritional loss ratio and acquisition cost ratio.

Attritional loss ratio - current year for the three months ended March 31, 2026 was 54.5% compared to 51.9% for the three months ended March 31, 2025, an increase of 2.6 percentage points. The increase was primarily driven by a change in business mix, including more casualty reinsurance and specialty insurance business.

Attritional loss ratio - prior year for the three months ended March 31, 2026 was an unfavorable 2.4% compared to a favorable 2.9% for the three months ended March 31, 2025, an increase of 5.3 percentage points. The attritional loss ratio - prior year for the three months ended March 31, 2026 was primarily driven by additional loss information in relation to the Baltimore Bridge collapse. In addition, casualty business protectedby the loss portfolio transfer ("LPT") discussed in Note 6, Reinsurance, benefited from favorable development in the underlying reserves of $0.1 million and a change in the deferred gain of $0.2 million, for a total net positive earnings impact of $0.3 million. The attritional loss ratio - prior year for the three months ended March 31, 2025 was primarily driven by favorable development in both our International and Bermuda specialty and property classes. In addition, casualty business protected by the LPT benefited from favorable development in the underlying reserves of $1.0 million, which was partially offset by a change in the deferred gain of $0.5 million, for a total net positive earnings impact of $0.5 million.

Catastrophe losses - current year and prior year development were $Nil for the three months ended March 31, 2026. Catastrophe losses for the three months ended March 31, 2025 were as a result of the California wildfires of $159.7 million, partially offset by favorable prior year development of $9.2 million.

(1) Prior to non-controlling interest performance incentive allocation

Total net realized and unrealized gains (losses) on investments and net investment income (loss) -TSHF, prior to non-controlling interest, returned income of $176.6 million and $204.0 million for the three months ended March 31, 2026 and 2025, respectively. This includes the fund's returns, net of investment management fees.

Net investment income, net of non-controlling interest - TSHF, returned income of $93.1 million and $103.6 million for the three months ended March 31, 2026 and 2025, respectively. This includes the fund's returns, net of investment management fees and performance incentive allocations. The aggregate incentive allocation to which the investment manager is entitled is included in "Net income (loss) attributable to non-controlling interest" in our GAAP financial statements.

TS Hamilton Fund produced returns, net of investment management fees and performance incentive allocations, of 4.3% and 5.5% for the three months ended March 31, 2026 and 2025, respectively.

For the three months ended March 31, 2026, TS Hamilton Fund experienced gains in single name equities trading within the equity market neutral vehicles STV, ESTV, and ATV. Gains in single name equities trading were led by the U.S., followed by China onshore and Europe. TS Hamilton Fund also experienced gains from macro trading within the systematic macro vehicle, FTV, the relative value macro vehicle, HTV, and the scientific discretionary macro vehicle, NTV. Gains in macro trading were led by commodities in FTV. Gains in TS Hamilton Fund were partially offset by losses from macro trading within the relative value rates vehicle, KTV.

For the three months ended March 31, 2025, TS Hamilton Fund experienced gains in single name equities trading within the equity market neutral vehicles STV, ESTV, and ATV. Gains in single name equities trading were led by the U.S., followed by East Asia. TS Hamilton Fund also experienced gains from macro trading within the systematic macro vehicle, FTV, the relative value macro vehicle, HTV, the scientific discretionary macro vehicle, NTV, and the relative value rates vehicle, KTV. Gains in macro trading were led by commodities in FTV and equities in HTV.

Total net realized and unrealized gains (losses) on investments and net investment income (loss) - other, returned income of $0.6 million and $63.8 million for the three months ended March 31, 2026 and 2025, respectively. Income for the three months ended March 31, 2026 was driven by investment income on a larger portfolio of higher-yielding assets, offset by negative mark-to-market returns. Income for the three months ended March 31, 2025 was primarily driven by investment income and positive mark-to-market returns.