Mark Cuban has some revealing if unduly cynical thoughts about the stock market, from someone who was on the inside in the 1990s. (Yet again, Cuban writes with the touching naivete of a guy who thinks you can speak freely about the stock market in this country without getting sued at the drop of a hat). While I can’t agree with Cuban’s wholesale cynicism about the market, it’s amazing how often investors, like sports fans and sports teams, forget that something that is a good buy at one price can be a terrible investment at a different price. His story about a company called Gandalf is a great example of the phenomenon.