Know When to Fold’em: When Is the Right Time to Sell a Stock? By Larry D. Spears, Money Morning
Nine Good Reasons for Selling a Stock
1. Sell when the reason you purchased the stock in the first place no longer applies.
2. Sell if the stock's not keeping pace with the overall market or its specific sector.
3. Sell if the stock far outpaces the overall market or the rest of its sector.
4. Sell at least some of your shares if a "hot" stock begins to dominate your portfolio.
5. Sell if the long-term trend the company benefits from shifts in a different direction or dies entirely.
6. Sell when the overall economic trend turns downward or the prospects for a given sector go sour.
7. Sell when your stop is triggered.
8. Sell to take advantage of a better opportunity.
9. Sell when everyone else is buying.
http://moneymorning.com/2010/04/06/sell-a-stock/