This retailer has stood tall through thick and thin in the economy and stock market.I don't generally buy stocks with the intention of selling them within a short period. However, there are situations -- whether business-specific, industry-related, or economy-related -- that cause me to finally cut ties with a stock.On the other hand, there are a few stocks in my portfolio that I refuse to cut ties with, regardless of the environment. One of those is retail giant Walmart (WMT +0.12%). Walmart is a staple in ...