Arch Capital Group Ltd. ACGL reported first-quarter 2021 operating income per share of 59 cents, which surpassed the Zacks Consensus Estimate by 18%. The bottom line also increased 28.3% year over year.The company’s results benefited from improved premiums. However, higher costs and elevated catastrophic losses stemming from several weather-related events as well as the COVID-19 pandemic partly dampened the results.Arch Capital Group Ltd. Price, Consensus and EPS Surprise Arch Capital Group Ltd. price-consensus-eps-surprise-chart | Arch Capital Group Ltd. QuoteBehind the HeadlinesGross premiums written improved 19.9% year over year to $3.4 billion. Net premiums written also climbed 17.4% year over year to $2.5 billion on higher premiums written across its Insurance, Reinsurance and Mortgage segments.Net investment income plunged 31.9% year over year to $98.9 million.Operating revenues of $2 billion, however, rose 7.8% year over year.Total expenses of $1.8 billion increased 14.6% year over year due to higher losses and loss adjustment expenses, acquisition costs, other operating expenses, corporate costs as well as interest expense.Pre-tax current accident year catastrophic losses, net of reinsurance and reinstatement premiums, of $188.3 million increased about 59% from the prior-year quarter. The surge in catastrophic losses — which includes $0.6 million of COVID-related losses — resulted from several weather-related events including winter storms Uri and Viola.Arch Capital’s underwriting income increased 20.7% year over year to $185.9 million. Combined ratio improved 80 basis points (bps) to 90.7.Segment ResultsInsurance: Gross premiums written increased 17.2% year over year to $1.4 billion, while net premiums written climbed 20% to $994.8 million. This growth can primarily be attributed to rate increases, new business opportunities and growth in existing accounts, partially offset by deterioration in the travel business.Underwriting income was $18.4 million, which rebounded from the year-ago loss of $28.2 million. Combined ratio improved 620 bps to 97.7Reinsurance: Gross premiums written improved 31% year over year to $1.5 billion, while net premiums written increased 25.3% to $999.1 million. The growth was driven by rate increases and new business.Underwriting loss was $19.8 million, which widened from the year-ago loss of 9.4 million. Combined ratio deteriorated 90 bps year over year to 102.9.Mortgage: Gross premiums written improved 6% year over year to $391.2 million, while net premiums written increased 3.3% to $335.2 million. The improvement can be primarily attributed to growth in Australian single premium mortgage insurance, partially offset by a lower level of U.S. primary mortgage insurance in force on monthly premium policies.Underwriting income increased 1.4% year over year to $200 million. Combined ratio improved 170 bps year over year to 45.8. The U.S. primary mortgage insurance business generated $27 billion of new insurance written, up 60.7% year over year, driven by a significant increase in mortgage originations in the market.Financial UpdateArch Capital exited the first quarter with cash of $941.9 million, which climbed 3.9% from Dec 31, 2020. Debt was $2.9 billion as of Mar 31, 2021, which inched up 0.01% from Dec 31, 2020.As of Mar 31, 2021, book value per share was $30.54, up 17% year over year.Annualized operating return on average common equity was 7.8% for the first quarter, which expanded 70 bps year over year.During 2020, net cash provided by operating activities was $762.8 billion, which increased 25% year over year.The company bought back 5.3 million shares for $179.3 million in the reported quarter.Zacks RankeArch Capital currently carries a Zacks Rank #3 (Hold). You can see the complete list of today’s Zacks #1 Rank (Strong Buy) stocks here.Performance of Other Property & Casualty (P&C) InsurersOf the insurance industry players that have reported first-quarter results so far, The Travelers Companies TRV, W.R. Berkley Corporation WRB and RLI Corporation’s RLI earnings beat the Zacks Consensus Estimate.Zacks Names “Single Best Pick to Double”From thousands of stocks, 5 Zacks experts each have chosen their favorite to skyrocket +100% or more in months to come. From those 5, Director of Research SherazMian hand-picks one to have the most explosive upside of all.You know this company from its past glory days, but few would expect that it’s poised for a monster turnaround. Fresh from a successful repositioning and flush with A-list celeb endorsements, it could rival or surpass other recent Zacks’ Stocks Set to Double like Boston Beer Company which shot up +143.0% in a little more than 9 months and Nvidia which boomed +175.9% in one year.Free: See Our Top Stock and 4 Runners Up >>Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report The Travelers Companies, Inc. (TRV): Free Stock Analysis Report W.R. Berkley Corporation (WRB): Free Stock Analysis Report RLI Corp. (RLI): Free Stock Analysis Report Arch Capital Group Ltd. (ACGL): Free Stock Analysis Report To read this article on Zacks.com click here. Zacks Investment Research