What Is Delta in the Context of Options Trading?

Delta is one of the "Greeks" and measures the sensitivity of an option's price to a $1 change in the price of the underlying asset. A Delta of 0.60 means the option price will theoretically change by $0.60 for every $1 movement in the underlying asset.

Call option Deltas range from 0 to 1, while put option Deltas range from -1 to 0. It also approximates the probability of the option expiring in-the-money.