Our fiscal cliff is threatening the global rally—and our presidential election isn't making anything better. Both carry an uncertainty that makes investors nervous. Yes, stocks rallied after the European Central Bank said it would go on an unlimited bond-buying frenzy and the Federal Reserve said it would start a third round of asset purchases. Economists continue to emphasize that a monetary stimulus can lift stocks only so far—further market advances will have to be done economic growth in the U.S. Economists project the U.S. economy will grow 2.2 percent this year and 2.05 percent in 2013.