As of the latest data point for Q1'26 (2025-11-23), Costco's P/E Ratio stands at 46.122. This reflects a notable decrease from the previous quarter, Q4'25, where the P/E Ratio was 50.058. Analyzing the period from Q3'23 to Q1'26, the P/E Ratio generally exhibited an upward trend, rising from 37.86 in Q3'23 to a peak of 57.156 in Q3'25. After reaching this high, the ratio experienced a downward correction, declining over the following quarters to the current level. The data suggests a period of valuation expansion followed by recent contraction, indicating shifting investor sentiment or changes in earnings expectations over the observed timeframe.