Using the Greeks
Risk can be determined in several different ways. The most commonly used method of determining the risk to a position is using the Greek risk measurements. The Greeks can assist you in determining the risk/reward of a potential position, as well as ongoing risk/reward for existing positions.
The Greeks measure expected change of specific factors that influence the price of the option. Specifically, Greeks tell you what can happen to your position if price, time, interest rates, or volatility change.