Costco's P/E ratio as of March 15th, 2024 is 47.37. This indicates that the stock may be overvalued compared to the average P/E ratio of 20.43 for the Retail Trade industry. However, it's important to note that Costco has a strong brand and loyal customer base, which may justify a higher P/E ratio. It's always recommended to do further research and analysis before making any investment decisions.