It won't be easy for Costco stock to repeat this incredible performance.You certainly don't have to chase hot tech stocks to earn great returns in the market. As of May 20, an investor that bought $1,000 worth of shares in Costco Wholesale (COST 1.68%) five years ago would have $3,467, including dividends, for an annualized return of 28%. It completely left the S&P 500 index in the dust. It's highly unusual for a large retailer to deliver that sort of gain to investors. Let's look at what caused the stock t ...