Costco is hovering around an all-time high and continues to put up solid results. Costco Wholesale (COST 1.47%) has been a market-outperforming retailer in a growth-driven market. Technology is the only sector that has outperformed the S&P 500 over the last five years. But Costco has done even better, with the stock up 238% in the last five years compared to a 193% gain in the tech sector and a 92% gain in the S&P 500. Costco's strong performance is based on solid fundamentals and investor optimism. Costco ...