In general, option strategies can be broken down into the following four categories.
Debit Strategies:
In debit option strategies, the exposure of the trade is limited to the amount of the debit incurred. Therefore, the only requirement is the cash needed to place the trade.
Credit Strategies:
In most credit strategies, the exposure can be defined based on the differences between the various strike prices involved. These differences are used to calculate the maximum loss potential and the margin requirement is then based on this maximum.
Naked Put Strategies:
Naked put strategies have significant, but defined downside exposure. This potential exposure can be measured by the current stock price and the option premium. Using a formula that incorporates these two factors, a margin requirement is calculated. If the price of the underlying security falls, this margin maintenance requirement will generally increase.
Naked Call Strategies:
Naked call strategies have unlimited exposure as the price of the underlying security has no defined limit as to how high it can rise. Using a formula that incorporates the current price of the security and the current premium on the call option, a margin requirement is calculated. If the price of the underlying security rises, this margin maintenance requirement will generally increase as well.