This article first appeared on GuruFocus.

Costco (NASDAQ:COST) has entered the tariff arena in a way that could reshape how major retailers navigate policy uncertainty. After weeks of smaller firms and state officials challenging President Trump's use of emergency economic powers to impose global duties, Costco filed its own complaint on Nov. 28, signaling that even the sector's most disciplined operators may now see legal action as a strategic hedge. The timing is no accident. The Supreme Court heard arguments on Nov. 5, where several justices questioned the administration's approach, and the fast-track schedule has left companies racing to protect their eligibility for refunds should the justices eventually rule against the tariffs. Costco's lawyers said the uncertainty around those refunds prompted the filing, especially after Customs and Border Protection denied the company's request to extend the schedule for finalizing tariff determinations.

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That denial could be the pressure point that pushed Costco to act. The company's suit doesn't disclose how much it has paid in duties, but management has been candid all year about the operational strain. Tariffs have primarily hit Costco's non-food categories, forcing a mix of tactical movesrerouting goods to non-US markets, ordering inventory early, consolidating suppliers, and even changing merchandising when certain items become too expensive. CFO Gary Millerchip described an ongoing effort to find efficiencies with suppliers, a process that could soften the blow but not eliminate the unpredictability. Earlier commentary showed how Costco has selectively adjusted pricing: keeping bananas and pineapples steady due to their importance to shoppers, while raising flower prices when costs rose and customer sensitivity was lower.

Costco stands out because most large retailers have not taken the legal route, even as tariff volatility has disrupted electronics and apparel pricing and contributed to more cautious consumer behavior. Yet other big namesRevlon Consumer Products Corp. and Kawasaki Motors Manufacturing Corp.have recently joined the litigation wave, a sign that more companies may be positioning themselves for whatever outcome the Supreme Court delivers. The White House has argued that not upholding the tariffs could carry significant economic consequences, while lower courts have allowed the duties to remain in place during the appeal. Costco's advantage may come from its scale and tight assortment, but executives have acknowledged that predicting future pricing under shifting tariff rules could be increasingly difficult, leaving investors watching both the Court and Costco's playbook for clues on how the sector adapts next.