Tariff-Related Lawsuits Could Hurt Costco Stock, but the Reason Why May Surprise You

A customer lawsuit seeking tariff refunds after the Supreme Court struck down the tariffs could force Costco to refund duties and pressure near-term profits. Costco reported $137 billion in revenue for the first half of fiscal 2026 (ended Feb. 25), up 9% year over year, and roughly $4 billion in profit for the first two quarters, up 13% year over year, while the shares trade at a rich 51x earnings. The combination of potential refund costs and legal uncertainty creates downside risk to the stock's valuation, and investors are advised to avoid paying 51x earnings until the issue is resolved.

Analysis

Legal/refund uncertainty creates an earnings and working-capital transmission mechanism few investors have priced: claims and retroactive adjustments tend to hit gross margin first, then cash flow as refunds and reimbursements are reconciled with suppliers over 1–3 quarters. That cadence forces temporary liquidity use (reserves, increased payables) and can induce promotional behavior to protect foot traffic, compressing unit economics even if membership retention stays healthy.

Competitors with lower multiples and more flexible pricing (notably the big-box general merch players and home-improvement chains) can exploit a near-term reversion trade by selectively funding promotions or expanding loss-leader assortments; suppliers facing multi-jurisdictional repayment exposure will prioritize customers with steadier payment terms, subtly advantaging retailers who can absorb short-term margin pressure. Logistical second-order effects—rerouted sourcing, longer lead times and concentrated supplier negotiations—raise inventory risk and could depress in‑stock rates during peak seasonal windows over the next 2–6 quarters.

Key catalysts to watch are: judicial rulings and any material supplier settlements (days–months), the next quarterly guidance update (weeks–months), and membership renewal trends (quarterly cadence). Tail risks include class-action expansion or regulatory scrutiny that would broaden refund liabilities beyond current estimates; conversely, a quick supplier indemnity/insurance recovery would be a technical relief event and likely trigger a sharp multiple re-rating. Volatility is the tradeable signal here — not the headline itself.

Key Decisions for Investors

• Pair trade (3–9 months): short COST / long WMT, equal notional. Rationale: capture multiple compression and relative margin resilience at the cheaper peer. Target relative outperformance 8–15%; stop if pair moves against you by 6% on a mark-to-market basis.
• Options hedge (4–9 months): buy a COST put spread (buy ~25% OTM put, sell ~40% OTM put) sized to cover 30–50% of your notional exposure. Risk = premium paid; reward = ~3–5x if downside materializes. Use around earnings or a legal/court milestone to maximize IV entry.
• Long defensive exposure (6–12 months): add to HD or WMT (favor the lower multiple, stronger FCF mover) to capture rotation out of richly priced names. Position tilt 1–2% NAV with a 12–18% return target if market favors valuation reset.
• Volatility play (weeks–months): buy short-dated COST strangles ahead of next guidance/earnings to monetize a probable IV spike, then trim into any post-event mean reversion. Risk is premium decay; reward is asymmetric if litigation/settlement news surprises.