And so people, and specially hedge funds, who act in this way based on they are thinking that the merger is more likely to ocur or less likely to ocur based on their reasearch or maybe they have some quantitative models or may they have some information other people don't have that might be legal or might be otherwise they would place these bets; the people who think that the merger will happen will buy expecting it to go to 10 dollars the people who think it won't they would short it expecting it to go to 5 dollars. 