Wallstreet has so much diverged from the real world that their financial innovations benefit world as much as invention of new casino game. On the other hand their inventions can hurt economy a lot because they invite to their casino people who apart from gambling use their money for developing economy. They lure them with high and fairly sure profits, but since investing in financial instruments is nothing more than gambling, probable high profits are offset by fairly rare but absolutely devastating crashes that damages players that haven't completely parted with real world economy yet. And that's really harmful.