Key Takeaways BRK.B's insurance units rely on disciplined underwriting expense management to sustain profits.Effective cost control boosts BRK.B's combined ratio and strengthens its investment float.BRK.B stock is up 8% YTD. The consensus estimate for 2025 EPS indicates a year-over-year decline.Berkshire Hathaway’s (BRK.B) insurance operations serve as the cornerstone of its business model and remain a key growth engine. GEICO, Berkshire Hathaway Reinsurance Group and Berkshire Hathaway Primary Group are th ...