Costco’s Lawsuit for Trump-Era Tariff Refunds Amid Supreme Court Legality Review

This analysis is based on the CNBC report [1] published on December 1, 2025, which details Costco’s lawsuit for tariff refunds. On that date, Costco filed in the U.S. Court of International Trade to secure refunds of tariffs paid under Trump’s IEEPA orders, amid uncertainty about refund guarantees if the Supreme Court strikes down the tariffs. The Supreme Court heard oral arguments on November 5, 2025, with lower courts previously ruling against the tariff authority, and the Court accepting an expedited review [4][5].

Key market data from internal sources [0] shows Costco closed at $911.96 on December 1, 2025, with a market cap of $404.16B and a 10-day price increase of 1.78%. Broader indices had mixed performance: NASDAQ up 0.45%, Dow Jones down 0.61%. The American Action Forum estimates $250B in annual tariffs and $90B in potential refunds [5]. Reddit discussion reflects that a ruling against tariffs could cause markets to “skyrocket” [1], linking tariff reduction to lower inflation and higher bond prices.

1. A favorable Supreme Court ruling would directly benefit importers like Costco, Walmart, and Target by reducing costs and potentially boosting earnings.
2. Tariff reductions could ease inflationary pressures, leading to lower interest rates and higher bond prices, as suggested by market sentiment [1].
3. There is a discrepancy between public expectations (refunds to consumers) and legal reality (refunds to importers), which could trigger political and public backlash.
4. The Supreme Court’s expedited review indicates the case’s significance, but the ruling timeline remains uncertain, with estimates ranging from late 2025 to spring 2026 [6].

• Importers could receive substantial refunds (up to $90B total), improving profit margins [5].
• Lower tariffs may reduce import costs, easing inflation and supporting consumer spending [1].
• A favorable ruling could boost market sentiment, potentially lifting stock and bond prices.

• Supreme Court ruling in favor of maintaining tariffs: no refunds, continued cost pressures for importers [5].
• Refund implementation delays due to logistical or legal challenges [7].
• Public and political backlash if refunds go to importers instead of consumers [1].

• Costco’s current price (2025-12-01): $911.96; market cap: $404.16B [0].
• Estimated annual tariffs at stake: $250B; potential refunds: $90B [5].
• Supreme Court oral arguments held November 5, 2025; ruling timeline uncertain [4][6].
• Costco’s 10-day price trend: +1.78% [0].
• Costco’s lawsuit seeks refunds to address uncertainty about refund eligibility post-ruling [2][3].