The warehouse retailer's shares are up by more than 30% so far this year.Costco Wholesale (COST 0.48%) has been a long-term winner for investors. The company has delivered spectacular earnings growth, with revenue and net income climbing even during difficult periods such as the early days of the pandemic. And its share performance has followed. The stock has advanced by nearly 200% over the past five years, and is up by more than 30% so far in 2024.As a result, the share price has reached more than $800 an ...