A term describing the greater percentage of profit or loss potential when a given amount of money controls a security with a much larger face value. For example, a call option enables the owner to assume the upside potential of 100 shares of stock by investing a much smaller amount than that required to buy the stock. If the stock increases by 10 percent, for example, the option might double in value. Conversely, a 10 percent stock price decline might result in the total loss of the purchase price of the option. A call holder has leverage with respect to a stock holder - the former will have greater percentage profits and losses than the latter, for the same movement in the underlying stock.