There's a good reason to sell and a bad reason to sell - people are selling for the bad reason right now At one point on Wednesday the Dow was off 550 points as each of the major US stock indexes fell by more than 3%. In an afternoon email, Rich Barry at the NYSE summed up what's going on down on the floor of the stock exchange, and his simple explanation is that on Wall Street you get people selling stocks for two reasons: intellectual and non-intellectual.