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

Same yardstick, side by side (as of September 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.

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 UNP 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 UNP 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

Union Pacific Corporation, headquartered in Omaha, Nebraska, operates the Union Pacific Railroad, which spans more than 30,000 route miles across 23 western U.S. states. The railroad hauls a diversified mix of freight including bulk commodities (coal, grain, fertilizers), industrial products, chemicals, automotive goods, and intermodal containers, connecting U.S. manufacturers, farmers, and ports to domestic and global markets. Revenue is generated through freight rates negotiated with shippers, fuel surcharge mechanisms tied to diesel prices, and ancillary services. The company's precision scheduled railroading (PSR) model focuses on maximizing asset utilization, train length, and velocity while minimizing cost per unit, which has driven sustained operating ratio improvement.

Full UNP 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.
• UNP drivers: Pricing Power and Volume Momentum; Operational Efficiency and PSR Upside.

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 UNP, the most immediate risk is regulatory: the Surface Transportation Board's review of the Norfolk Southern merger is drawing active opposition from competitor CSX, which is mobilizing shippers and communities, and UNP has indicated it may walk away if approval conditions exceed a reported $750 million cost threshold, which could also trigger a large breakup fee.

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; UNP 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 UNP 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.

UNP. At roughly 21x trailing earnings, UNP trades near its own 3-year and 5-year historical average P/E, suggesting the market is pricing in steady but not exceptional growth rather than a valuation premium. The ~29% net profit margin (net income of $7.1 billion on $24.5 billion in revenue for 2025) reflects the structural cost advantages of the U.S. Class I railroad oligopoly and the efficiency gains from PSR. The pending Norfolk Southern merger introduces both meaningful upside (synergies of at least $2 billion in incremental net revenue projected) and execution and regulatory risk that investors are still digesting.

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); UNP shows revenue (full-year 2025) ~$24.5 billion, net income (full-year 2025) ~$7.1 billion, eps diluted (full-year 2025) ~$11.98, adjusted operating ratio (full-year 2025) ~59.3%.

BRK-B and UNP 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 UNP exposure against your real portfolio. It is not an investment adviser.