In options trading, Delta is a measure of an option’s sensitivity to changes in the price of the underlying asset. It is the ratio of the change in the price of the option to the change in the price of the underlying asset. Delta values range from 0 to 1 for call options and -1 to 0 for put options. A delta of 0.5 means that for every $1 increase in the price of the underlying asset, the option’s price will increase by $0.50. Delta is one of the “Greeks,” a group of metrics used to measure various aspects of options trading.