Thank you, Tom. Good morning, everyone. The start of 2024, we began reporting Markel Group segment operating income for our investments, ventures and insurance engines. Operating income is a key driver of our intrinsic value and long-term incentives. If you must pick one metric for our scorecard, operating income is the best place to start. We use 5-year periods to keep that scorecard because the expected volatility in the mark-to-market of our equity portfolio normalizes over longer periods. Over the past 4 calendar years, plus the first 6 months of this year, we have accumulated operating income of just over $11 billion. In the second quarter of 2025, consolidated operating income was $1.1 billion versus $410 million in the same period one year ago. The biggest driver of the year-over-year difference was changes in unrealized gains on the equity portfolio, which flows through GAAP operating income, distorting quarterly year-over-year comparisons. Within our insurance engine, which includes our Markel Insurance business, along with our State National and Nephila businesses, operating income was $128 million for the second quarter of 2025 versus $177 million in the same period one year ago. The decline in year-over-year was driven by less favorable prior year loss development and a higher expense ratio. Markel Ventures revenues were up 7% in the second quarter or $1.55 billion in the second quarter of 2025 versus $1.45 billion in the comparable period 1 year ago. Ventures operating income was up 17% year-over-year in the second quarter of 2025 or $208 million in the second quarter this year versus $177 million in the same period last year. These increases were driven by the contributions from EPI, which we began consolidating in the first quarter of 2025 and Valor, which we acquired last year, along with increases within our construction services businesses, partially offset by decreases from our transportation businesses. Since EPI and Valor are newer businesses to the family, we thought context on each would be helpful. The multiyear nature of EPI's education placement contracts provides stability to its quarterly results. The company sponsors an exchange visitor program for teachers. It serves school districts in the Southeast and Mid-Atlantic U.S. states. It serves a market with favorable long-term demand trends. This, plus EPI's sterling reputation, gives that business good revenue and earnings visibility with a steady growth profile. Valor services the cyclical, commercial and residential construction markets, where the latter has experienced softening conditions of late. However, the growing importance of proper erosion control and storm water protection provides Valor with a backdrop for growth over cycles. Our equity finance approach and capital discipline factors in cyclicality when we underwrite businesses. We are thrilled to welcome both businesses to the family. Turning over to our investments. Investments operating income was $822 million for the second quarter of 2025 and $100 million for the same period one year ago. Our equity portfolio returned 5.4% in the second quarter with $597 million in mark-to-market gains, which are included in our Q2 2025 operating income versus $116 million in losses in the comparable quarter last year. While we expect to see short-term fluctuations in our equity portfolio when measuring them on a quarterly basis, over the long term, our public equity portfolio has created excellent returns and now has a cumulative unrealized gain of $8.3 billion. We continue to take advantage of our low-cost and tax-efficient structures, long-term holding lens and allocating a portion of our incoming cash flows to compound capital in our public equity portfolio. Net investment income was $228 million in Q2 2025 versus $220 million in Q2 2024. While net investment income from our fixed portfolio increased, declines in short-term interest rates caused the year-over-year increases in interest income to moderate. In Q2 2025, our fixed income book yield was 3.5% and our short-term investments yield was 3.9%. We continue to add new fixed income investments at higher yields, approximating 4.2% versus maturing bonds with yields approximating 3.4%. 96% of our bond portfolio was held in fixed income securities that are rated AA or better. As we have previously discussed, we seek to materially match our fixed income portfolio in both duration and currency to our net loss reserve liabilities. During the second quarter, the dollar weakened against our 2 primary transactional foreign currencies, the Euro and the British pound. We reported a net loss from foreign currency in the quarter of $192 million, which was substantially offset by positive movements in foreign currency within our fixed income portfolio that is included within other comprehensive income. During the second quarter, we also made a change to our capital stack through the redemption of our $600 million 6% preferred stock. The coupon rate on that instrument would have reset to current market rates, exceeding 10% had we not redeemed the security this past quarter. I will now spend a little more time discussing our Markel Insurance underwriting operations, our largest cornerstone operating business. First, I want to call attention to the changes in our external reporting this quarter within our insurance operations to align with our recent organizational and management changes. We have resegmented our insurance operations and are now reporting our Markel Insurance business under Simon's leadership as one segment. As Tom mentioned, this new segment combines our previous insurance and reinsurance segments while providing more detail by breaking this segment into 4 operating divisions: US Wholesale and Specialty, Programs and Solutions, International and our Global Reinsurance division, which we have placed into runoff. We believe our expanded disclosures will help investors better understand the performance and underlying drivers of our insurance business going forward. You can see a breakdown of our quarterly and year-to-date results by operating division within our 10- Q. These changes are an initial step in our commitment to adapt and improve our external reporting. We expect to make further improvements to our reporting in the second half of this year and look forward to providing updates on our progress. I'll now provide a bit more detail on the results of our new Markel Insurance segment. Underwriting gross written premiums were down 2% for the quarter and up 1% on a year-to-date basis versus the comparable period last year. The decline in gross written premiums in the second quarter was driven by a 26% decline from Global Reinsurance due to the timing of renewal on large contracts and a decline of 5% with our US Wholesale and Specialty division due to the impact of exiting our U.S. risk-managed D&O product line. Programs and Solutions gross written premiums were up 8% in the second quarter versus the same period one year ago, driven by growth in personal lines. Further, International was up 5% in the second quarter year-over-year with growth across multiple product lines. For all of Markel Insurance, net earned premium was up 3% on a consolidated basis in the second quarter and 1% year-to-date versus the same period one year ago. Our more modest earned premium growth reflects growth within many areas of our portfolio, offset by the impact on gross written premiums from the underwriting actions in certain U.S. casualty and professional liability lines that we've taken to improve profitability. We expect the impact on earned premiums from these underwriting actions to reduce in the second half of this year while continuing to improve our overall attritional loss ratio. The Markel Insurance combined ratio was 96.9% versus 93.8% in the same quarter one year ago. Adverse development in certain now discontinued product lines negatively impacted our combined ratio for the quarter. Our U.S. and European risk-managed D&O professional liability lines added $127 million or 6 points to the second quarter overall combined ratio. Adverse development within our Global Reinsurance division added $50 million or 2 points to the Markel Insurance combined ratio. Further, losses from our collateral protection CPI product added another $26 million or 1 point to our current accident year attritional loss ratio. Excluding the impact from these run-off products, our Markel Insurance combined ratio for the quarter is in line with our long-term targets. Our current accident year's loss ratio was 64.5% in the second quarter of 2025 versus 66.6% in the same period 1 year ago, reflecting the impact of our underwriting actions, along with lower losses on our CPI product this year versus last year. Prior year loss development was 3.8% favorable on the combined ratio in the second quarter of 2025 versus 7.2% favorable in the comparable period last year. The lower favorable development year-over-year is the result of the reserving actions I just discussed in our runoff risk-managed D&O and global reinsurance product lines, while our ongoing book produced favorable loss takedowns, most notably within our property and marine and energy product lines. Our expense ratio was 36.3% in the second quarter of 2025 versus 34.5% in the comparable period. 50 basis points of the increase was driven by onetime severance and increased holding company allocations related to professional fees. The remainder was driven by increases in controllable expenses. We acknowledge that our expense ratio is not where it needs to be and are committed to reducing the controllable expense ratio within our insurance operations over time. As a reminder, beginning in 2023, we began taking a series of decisive actions, which we believe will better position the insurance business for profitable growth in the future. First, we took corrective actions through exiting several product lines, including primary casualty retail, business owners policy, risk managed excess construction, risk managed architects and engineers and CPI. Second, across our portfolio, we meaningfully reduced the construction mix in our casualty portfolio. We changed the terms and conditions to eliminate certain exposures to subcontractors, reduced limits on excess lines and implemented premium caps in challenging states. We have been achieving double-digit rate increases across the casualty portfolio this year and are walking away from risks that are not adequately priced. Third, we took further actions in 2025, including combining our risk-managed public D&O to a single access point within our Bermuda platform in our Programs and Solutions division and placed our U.S. and European platforms for this line into runoff. We also announced yesterday the transition of our Global Reinsurance business into runoff through the sale of renewal rights to nationwide. Premiums will continue to be earned in this division over the next 2 to 3 years due to the multiyear nature of contracts. Further, we will have some renewal contracts processed in the third quarter and premium writings going forward will largely be tied to adjustments on in-force contracts. We expect the accumulation of all these actions to be accretive to our 2025 and 2026 results, but they will put short-term pressure on Markel Insurance's gross written premium growth. We continue to hold loss reserves at a level that we believe is more likely redundant than deficient. Our reserve strengthening within our runoff books this quarter includes management actions intended to put these reserves at a level above our actuarial best estimate, creating a higher degree of confidence in the reserve adequacy. We expect our reserving philosophy to continue to produce prior year loss takedowns in future periods. We expect all of our actions to drive an improved attritional combined ratio in the back half of 2025 and continued improvement into 2026. With that, I will turn it over to Simon.