Definition:
Option is the right vested applicable to the purchaser, in respect of the issuer, to require within a set period the acceptance of the supply of the base instrument at the price defined in advance, referred to as the strike price (the sales option with delivery), or the payment of the amount dependent on the difference between the market price of the base instument and the strike price (the purchase option), or the amount dependent on the strike price and the market price (the sales option).