A trader who wants to speculate on an increase in price with a neutral to small increase in volatility can buy a Call Debit Spread, also known as a bull call spread. To form a Call Debit Spread, The key to a call debit spread is selling a call at a higher strike than you buy a call, all on the same expiration date.

The trader pays a debit for the whole position, called a premium, though this debit is smaller than the debit associated with buying a Call alone. In exchange for this price reduction, a Call Debit Spread gives up the theoretically unlimited profit associated with a Call as the max profit is limited to the width of the spread between the bought Call and the sold Call minus the debit paid.