Costco Wholesale closed the books on a record fiscal 2026 Thursday night, posting fourth-quarter profit and sales that beat Wall Street's targets — but the warehouse giant's own numbers show a chunk of that beat came not from shoppers, but from a refund check tied to President Trump's tariffs.

In its fourth-quarter results after markets closed, Costco reported net sales of $93.9 billion for the 16-week quarter ended August 30, up 11.2% from a year earlier, with total revenue of $95.7 billion beating the $94.9 billion analysts expected. Diluted earnings per share came in at $6.75, topping the Street's $6.55 estimate and up 15% from $5.87 a year ago. Comparable sales rose 9.4% companywide, and e-commerce sales jumped 19.5%. For the full fiscal year, net sales hit $297.2 billion and profit reached $9.23 billion, or $20.76 a share.

Where the "beat" really came from

Buried in the release is the catch: $0.15 of that quarter's per-share earnings, net of reinvestment, came from a one-time windfall — refunds Costco received under the International Emergency Economic Powers Act after successfully challenging import duties. Costco disclosed it collected $184 million in IEEPA tariff refunds during the quarter, describing the amount as "a little more than one-third" of what it ultimately expects back, according to a detailed breakdown of the quarter's tariff-refund accounting. Rather than pocket the windfall, executives said they funneled most of it straight back into lower shelf prices on staples like meat, beverages and household essentials.

"Our goal is to be the first to lower prices where we see opportunities to do so," chief financial officer Gary Millerchip told analysts on the earnings call, framing the price cuts as "giving a value back to our members for the tariffs that we pay" rather than a discounting strategy to chase growth.

Membership income, the metric investors watch most closely for signs of loyalty, climbed 7.3% to $1.85 billion for the quarter, with the company's cardholder base growing to 150.4 million and a worldwide renewal rate holding at 89.8%. Costco also said it opened 28 new warehouses in fiscal 2026, bringing its global total to 939, and plans to add 33 more in fiscal 2027.

Investors, however, largely shrugged. Costco shares, which had drifted lower into the print, ticked up only fractionally in after-hours trading — a sign the headline beat was already priced in and that traders are parsing how much of the strength is repeatable. As Costco's earnings coverage makes clear, the company issued no forward guidance for fiscal 2027, leaving analysts to model out how much of the tariff windfall — and the price cuts it funded — will continue once the refunds run dry.

Costco said it has already received a similar tranche of refunds in the first quarter of fiscal 2027 and intends to plow "the majority" of future payouts into further price reductions rather than profit. With no special dividend announced despite pre-earnings speculation, and comparable sales growth showing early signs of moderating from prior quarters, the next test comes when Costco reports its holiday-quarter results in December — the first look at whether tariff-funded discounts are translating into sustained traffic gains once the one-time accounting boost fades.