Risk.
Every decision is made with less than perfect information, and every decision entails taking a risk. The way to make sound decisions is to judge when you have enough information to move ahead and when the level of risk is acceptable. A decision-maker who takes no risk receives no reward. A decision-maker who disregards risk is a fool, a pauper, or both.
Financial decisions trade off risk and reward. An important corollary: There is no free lunch.
