Options include both a call and a put. The right to buy currency is a call option while the right to sell currency is put option. The option to buy US dollars and sell Japanese yen, for example, is a yen call and dollar put. The price that the buyer agrees to pay is called the strike price or exercise price and the amount of currency that may be bought or sold is called the principal. Options may be purchased on an exchange or over-the-counter and then bought and resold. US style options are purchased on an exchange and have a strike price, expiry date and contract size. Options bought over-the-counter are bought in interbank. Options offered in the interbank market are usually European style options where the terms of the contract are negotiated between the seller and buyer.
Swaps – A swap is a combination of a spot and forwards trade. A swap involves the trade of currency on a specified date and an agreement to trade it back at a later date. A swap provides you with an alternative to borrowing foreign currency. If you need liquidity in a currency, you may swap for the needed currency. This involves a spot transaction to initiate a trade and a forward transaction to buy back the currency in the future. Large banks and corporations tend to favor swaps. Individual investors rarely engage in swaps.