At the latest data point in Q3'26, Costco (COST) reported an ROE of 6.54%, an ROA of 2.54%, and an ROIC of 4.74%. These figures represent a slight recovery in ROE and ROA compared to the previous quarter, though ROIC continued its marginal decline. From Q4'23 to Q3'26, the chart reveals a consistent seasonal pattern where profitability metrics peak annually in the fourth fiscal quarter, notably reaching a high of 9.97% ROE and 3.37% ROA in Q4'24. While the overall trend for ROE and ROIC has experienced a gradual decline since their FY2024 peaks, the ROA has remained relatively stable, fluctuating within a tight range of approximately 2.16% to 3.39%. Despite the periodic volatility associated with fiscal year-end adjustments, the company maintains a healthy gap between ROE and ROIC, indicating effective use of financial leverage.