While it is true there are a few fundamental variables that will probably make or break your stock recommendation, do not forget there are externalities that you should also consider before heading into an interview to defend your pitch. For example, what happens to your earnings estimates if there is a currency move? What would reduced public sector spending from the U.S. Federal Government's impending fiscal cliff mean for your stock? What happens if interest rates move? What if Iran's nuclear development facilities are attacked by Israel or the United States? Could the U.S. elections affect your pitch's key drivers?
While the answers may or may not be perfectly clear, you should step back and consider how big picture issues could change you recommendation.