When it comes to foreign exchange derivatives,
A forward contract is not considered to be a foreign exchange derivative instrument.
If a currency appreciates above its strike price and a speculator has an American call option for that currency, the speculator can exercise the option and make a profit.
Currency futures contracts are mainly used by large banks while currency swaps are mainly used by individuals through their home computers.
American options is less flexible than a European option when it comes to the right to exercise the option at the strike price.
There is little opportunity for speculators to make money by using currency futures contracts.