In the latest fiscal period Q3'26, Costco reported a diluted EPS of -9.08 USD, marking a significant downturn compared to previous quarters. This represents a substantial year-over-year decline of -312.15%, a sharp reversal from the positive growth seen in earlier periods. Prior to the Q3'26 drop, the EPS showed a consistent upward trajectory from Q4'23 to Q2'26, typically peaking in the fourth quarter of each fiscal year, such as the 5.87 USD recorded in Q4'25. Throughout this timeframe, year-over-year growth remained positive and relatively stable, fluctuating between 2.55% and 29.01% before the abrupt collapse in the most recent quarter. This sudden shift indicates a major inflection point in profitability compared to the steady performance observed over the preceding eleven quarters.