Costco's Trump Lawsuit and Q1 2026 Earnings: What Investors Need to Watch

Costco has filed suit in the U.S. Court of International Trade seeking refunds should the Supreme Court rule that President Trump exceeded IEEPA authority for tariffs that reached up to 50% (and 145% on some Chinese goods), part of an ~ $90bn cost to U.S. importers; a decision is expected in early 2026. The company reported strong Q4 2025 results (net sales $86.16bn, net income $2.61bn, EPS $5.87; comparable sales +5.7%, e-commerce +13.5%) and generates roughly $275.2bn in annual revenue with ~11% merchandise margins, but unrecoverable tariffs and ongoing inflationary LIFO impacts (Q4 LIFO charge $43m vs prior-year $8m credit) pose material margin risk. Analysts model Q1 FY26 revenue of $67.15bn and EPS $4.24; investors will focus on management’s disclosure of disputed tariff exposure, timeline, sourcing shifts (including Kirkland expansion) and margin-protection plans on the upcoming earnings call.

Analysis

Market structure: Costco’s direct lawsuit makes it a binary focal point for tariff risk and potential upside if refunds are awarded. With $275bn revenue and ~11% merchandise margins, even a modest share of the ~$90bn industry tariff pool matters; a $300–500m hit equals ~1–2% of gross profit and would be visible to margins. Private‑label (Kirkland) and 15%+ e‑commerce growth are immediate defensive levers that improve pricing power in import‑sensitive SKUs.

Risk assessment: Near term (days–weeks) the Dec 11 earnings call is the key event; medium term (months) the Supreme Court ruling expected early‑2026 is binary and could trigger reimbursement vs permanent cost. Tail risks include adverse ruling + no refund mechanism (large one‑time charge), regulatory retaliation or consumer politicization; conversely a refund ruling could produce a multi‑quarter EPS tailwind. Hidden dependencies: Customs timing, supplier contract pass‑through clauses, and inventory location (domestic vs China) that determine true cash exposure.

Trade implications: Tactical: prefer directional exposure to COST but hedge legal/timing risk with options. Relative: long COST vs short WMT (Sam’s Club exposure isolated) to capture member‑model resilience; if management quantifies disputed tariffs ≤$500m, add to size. Use 3–9 month option structures (put spreads to cap downside into the SCOTUS decision; call overwrites if buying stock) rather than naked positions.

Contrarian angles: The market may underweight upside from potential refunds and overprice political contagion risk; historically (2018 tariffs) winners emerged from supply‑chain repricing within 6–12 months. Risk of escalation (other retailers suing or government pushback) is real but low probability; mispricings may appear in near‑dated options where implied vol rises on the Dec 11 call but falls sharply on clarity — tradeable gamma event.

Key Decisions for Investors

• Establish a 2–3% long position in COST ahead of the Dec 11 earnings call; immediately purchase a 3‑month 5%‑10% OTM put spread sized at 0.5% of portfolio to cap downside through near‑term legal disclosures.
• If management discloses disputed tariff exposure ≤ $500m or a clear remediation path, increase COST to 4–5% position within 7 trading days; trim if exposure > $1bn or if guidance implies >50bps sustained margin hit.
• Implement a pair trade: long COST (2%) / short WMT (1%) for 3–6 months to express relative upside from membership fees and private‑label insulation; unwind if COST vs WMT comp sales differential narrows to <100bps over a rolling 4‑week period.
• Buy March 2026 COST put spreads (10% OTM) sized to protect 1–2% of portfolio through the expected Supreme Court window; alternatively buy Jan 2027 calls (LEAP) as low‑cost asymmetric upside if implied vol spikes post‑ruling and stock underreacts.