Costco (COST) Stock Drops Nearly 20% in Back Half of 2025

Costco (COST) experienced a stock decline of nearly 20% in the latter half of 2025, reaching a low before year's end. Although this drop is part of a normal pattern, with share prices fluctuating over 15% in the past decade, it has led to concerns about valuation. Currently, Costco's P/E ratio has been around 45x at its lowest, which remains high compared to the S&P 500's average P/E of nearly 28x. Investors are advised to view Costco's stock as expensive, indicating a market caution toward its growth potential.