A long term investor will looks for a margin of safety in a stock. These type investors look for the company that has large cash reserves, no appreciable debt, or property worth more than the value of the business. This margin of safety helps protect shareholders over the long term against loss. However, when the broader market catches on and bids up the stock price this margin of safety moves from the balance sheet to the stock ticker. At this point even those engaged solely investing in long term will often sell as the anticipated gain from investing in this growing company has been reached.