The delta of a derivative security tells you the relationship between the underlying security's price and the security's price itself.

The delta represents the amount the price of the derivative will change when there is a change in the underlying price. For example, suppose you buy a call option with a delta of positive 0.5. The call option will increase by 50 cents for every $1 increase in the price of the underlying asset.

The delta of an option helps you determine the quantity of the underlying asset to buy or sell. This is known as delta hedging. Delta hedging involves trading another security to create a delta-neutral position, or a position that has a zero delta.

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You can use delta to hedge options by first determining whether to buy or sell the underlying asset. When you buy calls or sell puts, you sell the underlying asset. You buy the underlying asset when you sell calls or buy puts. Put options have a negative delta, while call options have a positive.

For example, suppose you buy 15 call option contracts with a multiplier of 100 with a delta of 0.2. You are long delta, so you must sell deltas to create a delta-neutral position. Next, you need to find the quantity of the underlying asset you need to hedge. To find the delta hedge quantity, you multiply the absolute value of the delta by the number of option contracts by the multiplier. In this case, the quantity is 300, or equal to (0.20 x 15 x 100). Therefore, you must sell this amount of the underlying asset to be delta neutral.