Shares of Costco Wholesale Corp (NASDAQ:COST) were last seen down 3.9% to trade at $906.42, after the retailer posted unfavorable same-store sales in its fourth quarter report. Helping to limit a steeper pullback, however, were the company's tariff-mitigation strategies and better-than-expected results, with earnings of$5.87 per share on revenue of $86.16 billion.Today's slide has COST trading at its lowest levels since April and on pace for its worst session since June. Costco's post-earnings track record ...