Equity options are contracts negotiated between a seller, or option writer, and a buyer, or option holder, based upon the exchange of securities at a given price, or strike price. There are two types of equity options: call options and put options. Call options grant the buyer the right to follow through with the purchase of a security at a given time based upon the established strike price. Those who buy call options are hoping that the value of the security will rise by the time they follow through with their purchase. When a contract for a call option is struck, the buyer can chose to follow through with the purchase at the specified time or opt out, but the seller is obligated to honor the transaction regardless.