Exercise (options)
The owner of an option contract has the right to exercise it, and thus require that the financial transaction specified by the contract is to be carried out immediately between the two parties, whereupon the option contract is terminated. When exercising a call option, the owner of the option purchases the underlying shares (or commodities, fixed interest securities, etc.) at the strike price from the option seller, while for a put option, the owner of the option sells the underlying to the option seller, again at the strike price. Styles. The option style, as specified in the contract , determines when, how, and under what circumstances, the option holder may exercise it. It is at the discretion of the owner whether (and in some circumstances when) to exercise it. Settlement. The option contract specifies the manner in which the contract is to be settled. Considerations. The following guidelines determine whether and when to exercise an option: Early exercise strategy. A common strategy among professional option traders is to sell large quantities of in-the-money calls just prior to an ex-dividend date. Quite often, non-professional option traders may not understand the benefit of exercising a call option  early, and therefore may unintentionally forgo the value of the dividend. The professional trader may only be 'assigned' on a portion of the calls, and therefore profits by receiving a dividend on the stock used to hedge the calls that are not exercised. Assignment and clearing. Assignment occurs when an option holder exercises his option by notifying his broker, who then notifies the Options Clearing Corporation (OCC). The OCC fulfills the contract, then selects, randomly, a member firm who was short the same option contract. The OCC then notifies the firm. The firm then carries out its obligation, and then  selects a customer, either randomly, first-in, first-out, or some other equitable method who was short the option, for assignment. That customer is assigned the exercise requiring him to fulfill the obligation that he agreed to when he wrote the option. Exercise by exception. In the U.S., for the convenience of brokers, who would otherwise have to request exercise of all in the money options, the Options Clearing Corporation will automatically exercise any option that is set to expire in the money by 1 cent or more. This is called "exercise by exception". A broker or holder of such  options may request that they not be exercised by exception. The price of the underlying security used to determine the need for exercise by exception is the price of the regular-hours trade reported last to the OCC at or before 4:01:30 pm ET on the day before expiration. This trade will have occurred during normal trading hours, i.e., before 4:00 pm. It can be any size and come from any participating exchange. The OCC reports this price tentatively at 4:15 pm, but, to allow time for exchanges to correct errors the OCC does not make the price official until  5:30 pm.