BRK-B vs MCY: Which Is the Better Buy in 2026?

Same yardstick, side by side (as of August 2026). Valuation lined up like this is most meaningful for two names in the same corner of the market, which these are. Figures are approximate; verify before investing.

Reading it: MCY is the cheaper of the two on forward earnings, but cheaper is not the same as better. Pair the valuation with growth (how far the forward P/E sits below the trailing P/E) and risk (beta) before you decide.

The metrics above tell you which is the marginally better business. The bigger risk for most people is not picking the slightly worse stock, it is over-concentrating. BRK-B and MCY share themes, so owning both, or adding either to what you already hold, can quietly push a large share of your portfolio into one bet.

This is the part a generic comparison page cannot answer, because it depends on what you own. Connect your brokerage and Walnut shows your real, combined BRK-B and MCY exposure, flags overlap with your existing positions, and tells you if adding one would tip you past a concentration you are comfortable with, read-only by default, with your login staying at your broker. Walnut is not an investment adviser.

Berkshire Hathaway is a diversified holding company that owns a wide range of businesses outright and holds a large portfolio of public stocks. Its foundation is insurance: GEICO, Berkshire Hathaway Reinsurance, and other insurers generate underwriting profit and, more importantly, float (premiums held before claims are paid) that Berkshire invests. In Q1 2026 insurance underwriting income rose to about $1.72 billion from $1.34 billion a year earlier. Beyond insurance, Berkshire owns the BNSF railroad, Berkshire Hathaway Energy, and consumer and industrial businesses such as Duracell, Dairy Queen, See's Candies, and Precision Castparts, alongside a stock portfolio historically anchored by names like Apple and American Express.

Full BRK-B guide

Mercury General Corporation, founded by George Joseph in 1961 and still headquartered on Wilshire Boulevard in Los Angeles, is the parent of Mercury Casualty, Mercury Insurance Company and related carriers. It sells private passenger auto, homeowners, renters, umbrella and small commercial auto cover in eleven states, though the business is not geographically balanced: California private passenger auto was about 53% of net premiums earned in the first half of 2026 and California homeowners another 18%. Distribution runs almost entirely through independent agents rather than direct advertising, which keeps acquisition costs different in shape from a Progressive or a GEICO, and the company carried roughly 2.36 million policies in force at mid-2026 (about 1.07 million auto, about 938 thousand homeowners). Joseph remains chairman and holds roughly a third of the shares, so control sits with the founding family rather than with institutions.

Full MCY guide

Both fit overlapping themes, but they are not interchangeable. The useful comparison is which set of drivers and risks you want exposure to.

• BRK-B drivers: Leadership transition to Greg Abel; Insurance float and underwriting.
• MCY drivers: Approved California rate increases still earning in; A rebuilt catastrophe reinsurance tower.

A faster-growing, richer-valued name usually swings harder, so it suits a longer horizon and a higher tolerance for volatility; a steadier, more cash-generative business suits a more conservative or income-minded investor. The honest test is which set of risks you could hold through a drawdown: The central 2026 risk is the leadership transition itself: Buffett's judgment and reputation were core to Berkshire's edge, and the market will test whether Greg Abel can allocate capital as effectively, especially with a record cash pile to deploy. For MCY, concentration is the first risk and it is structural, not cyclical: with roughly 70% of net premiums earned coming from two California lines, one bad fire season can erase several good underwriting years, as 2025's record $508 million of net catastrophe losses and 105.4% first half combined ratio demonstrated.

Growth-minded investors who believe the theme has years to run tend to accept the richer multiple for more upside; value-minded investors lean toward the cheaper forward earnings and steadier profile. Pick BRK-B if you believe its drivers more; MCY if you believe its. Many investors hold both, but since they share themes, that is a concentrated bet, not diversification. Decide deliberately and check overlap. For the full detail, see the BRK-B and MCY guides.

BRK-B. Figures are approximate and tied to the asOf date; verify live numbers before acting. Because accounting rules force Berkshire to mark its large stock portfolio to market each quarter, GAAP net income is noisy, so investors typically focus on operating earnings and book value per share rather than a simple P/E. The record cash balance means a meaningful part of the market cap is cash awaiting deployment, which affects how the business should be valued.

MCY. Second quarter net income of roughly $263.5 million (about $4.76 per diluted share) included roughly $86.5 million of realized investment gains, so operating income of about $195.2 million, or roughly $3.52 per share, is the cleaner read on underwriting. A combined ratio under 90% on a personal lines book is unusually profitable, which is why the shares carry about 2.1 times book rather than the 1.0 to 1.3 times more common for a California-concentrated insurer. Whether that multiple is durable depends on catastrophe load: strip 2025's 9.2 points of catastrophe losses out or add them back, and the same company looks like two different businesses.

Headline figures (approximate, Jul 2026): BRK-B shows operating earnings (q1 2026) ~$11.35 billion, up ~18% year over year (approximate; verify live), net earnings (q1 2026) ~$10.1 billion, but volatile due to mark-to-market swings on equities (approximate; verify live), cash and treasurys ~$397 billion at end of Q1 2026, a record (approximate; verify live), market cap ~$1 trillion (BRK-B ~$497 per share in mid-July 2026; approximate; verify live); MCY shows revenue (ttm) ~$6.3B, net premiums earned (q2 2026) ~$1.50B, up ~9.6% year over year, combined ratio (q2 2026) ~89.9% vs ~92.5% a year earlier, book value per share ~$51.20 at June 30, 2026 vs ~$43.64 at year-end 2025.

BRK-B and MCY are related but distinct: same themes, different businesses and risks. Neither wins in the abstract; the right pick is whichever thesis you actually believe, sized so you are not over-concentrated in one theme. Walnut can show your combined BRK-B and MCY exposure against your real portfolio. It is not an investment adviser.