Exchange Traded Options. An Exchange Traded Option (ETO) is a financial instrument whose price is derived from another. It that allows the trader to take a position in an underlying security to gain exposure to its movements. There are two types of ETO: puts and calls. A call provides the owner the right but not the obligation to buy a parcel of shares in an underlying security at a pre-determined price (the exercise price) on or before a pre-determined date (the expiry date). A put provides the owner the right but not the obligation to sell a parcel of shares in an underlying security at a pre-determined price (the exercise price) on or before a pre-determined date (the expiry date).