Delta - The delta is a measure of how an option's value changes with respect to a change in the price of the underlying contract. Positive delta means that the option position will rise in value if the stock price rises, and drop in value if the stock price falls. Negative delta means that the option position will theoretically rise in value if the stock price falls, and theoretically drop in value if the stock price rises. Call Delta is always Positive and Put Delta is always negative. The value of Delta ranges from -1 to 1