Delta

In finance, Delta makes a comparison between the change in the price of an asset to a consequent change in the price of its derivative. Delta is commonly used when dealing in options and is sometimes referred to as hedge ratio.

The option's delta is the variation rate of the option’s price in comparison to its underlying security's price. Put deltas range between 0.00 and +1.00, while call deltas range between 0.00 and -1.00.