The simultaneous sale of one option and purchase of another option that results in a debit to the investor's account. Thus, more funds are required for the purchase than are received from the sale. An example is the purchase of a 6-month call at a price of $500 and the simultaneous sale of a 3-month call at the same strike price for $300. This trade results in a debit of $200 plus commissions to the investor's account. Compare credit spread.