This Is My Favorite Warren Buffett Stock, and It's One of His Biggest Bets (Hint: It's Not Apple or Alphabet)

Berkshire Hathaway holds 151.6 million shares of American Express (≈$50 billion), making AMEX roughly one-fifth of Berkshire's equity portfolio and its No. 2 position behind Apple. American Express delivered 2024 revenue of $65.9 billion (+9% YoY) and EPS of $14.01 (+25% YoY), returned $7.9 billion to shareholders ($5.9 billion buybacks, $2.0 billion dividends), and reported continued momentum with Q2 revenue +9%/EPS +17% and Q3 revenue +11%/EPS +19%; a U.S. Platinum card refresh materially boosted new account acquisitions. The stock trades at a P/E of 24 (below Apple and Alphabet), reflecting attractive valuation against consistent double-digit growth and strong credit performance, though recession-driven spending declines, higher credit losses and intensifying competition remain material risks.

Analysis

Market structure: Premium-card issuers and co-brand partners are the primary beneficiaries as higher-margin spend and customer loyalty raise lifetime value; merchant-acquirers and mass-market card issuers face margin compression if premium cards capture disproportionate branded spending. Competitive dynamics favor firms with proprietary data, closed-loop benefits and differentiated rewards, which raises switching costs and allows modest pricing power expansion over 12–24 months.

Risk assessment: Key tail risks are a macro recession that lifts charge-offs by >150 bps within 12 months, or regulatory action that trims net interchange revenue by 25–40% — either would compress EPS by low-double to mid-double digits. Near-term (days–weeks) volatility will track macro prints and earnings cadence; medium-term (3–12 months) risk is execution on new-acquisition economics, and long-term (1–3 years) is structural competition from big-tech card partnerships.

Trade implications: Favor concentrated exposure to differentiated payments franchises while hedging cyclicality — size initial AXP exposure small (2–3% NAV) and layer to 4–6% on continued billings/margin outperformance. Use 6–12 month call spreads to capture upside and buy 3–6 month protective puts sized to 50–75% of position if charge-off trend deteriorates; consider dollar-neutral pair trades versus mass-volume networks to isolate premium-segmentation alpha.

Contrarian angles: Consensus underestimates acquisition-cost creep and underwriting dilution as product refreshes scale — front-loaded wins can reverse if CAC rises >30% YoY or activation falls. Historical parallels show premium-card share gains are reversible in downturns; unintended consequences include merchant pushback or co-brand fatigue that would disproportionately hurt revenue growth despite strong headline metrics.

Key Decisions for Investors

• Establish a staged long position in AXP equal to 2–3% NAV over 4–8 weeks; add to 4–6% NAV only if two consecutive monthly billings growth prints exceed company guidance or net interest margin expands by >10 bps. Set hard stop-loss to trim to half-size on a 12% drawdown and exit entirely if 3-month rolling charge-offs rise >150 bps.
• Implement a relative-value pair: long AXP (2% NAV) and short Visa (V) (1.5% NAV) to isolate premium-segmentation upside versus volume-driven networks; rebalance after each quarterly report and close the pair if relative performance gap narrows to <5% over 90 days.
• Use options to express asymmetric upside: buy 12-month AXP LEAP calls ~25% OTM sized at 0.75–1% NAV and finance by selling 3–6 month covered calls equal to 25–50% notional; alternatively buy 3–6 month puts (protect 50–75% of position) if consumer credit indicators (Delinquencies or Fed data) worsen for two consecutive months.
• Reallocate 3–5% from small regional banks/consumer discretionary into large-cap payment franchises and issuer leaders (AXP, MA, V) over 1–3 months; pause additions if regulatory guidance on interchange/merchant fees is issued within the next 30–90 days and reassess on clarity.