buffett on stop losses

"After buying a farm, would a rational owner … start selling off pieces of it whenever a neighboring property was sold at a lower price? Or would you sell your house to whatever bidder was available at 10:00 on some morning merely because at 10:00 a similar house sold for less than it would have brought on the previous day?"

The correct answer is no to both of Buffett’s questions. If a company is fundamentally sound, the price decline would make the stock more of a buy than a sell.However if the companies circumstances has changed then you should look at your position.