I've been digging through Costco's earnings and what stands out to me is the disconnect between operating performance and price action. The quarter was fundamentally solid. Comparable sales remained healthy, membership fee income continued to grow, traffic held up well, and digital sales accelerated. None of those metrics suggest a deterioration in the underlying business. Yet the stock sold off. My read is that this was more about valuation sensitivity than earnings quality. At roughly 50x+ trailing earnings, Costco is trading at a premium multiple that already assumes consistent execution and above-average growth. When a stock is priced that aggressively, even a small EPS miss, softer margin profile, or signs of moderating membership growth can trigger multiple compression. What caught my attention was that revenue growth remained intact, but there wasn't much in the report that justified further multiple expansion from current levels. The market wasn't looking for a good quarter.…