Yes; when I lose faith in a counter. Like I did with OCH in Jun 2009 - sold at 43% loss after holding it for only one year! It touched my selling price this week.
Of course I could have picked some when it touched 6 bob in Dec, but, hey, I have lost faith in it.
So you wonder why I had bought it the first place: I was very impressed by its SA acquisations. We all know how that went, don't we?
Nothing is real unless it can be named; nothing has value unless it can be sold; money is worthless unless you spend it.