It stands for in-the-money forward; a special case of an in-the-money option (ITM option) in which the spot price or rate of the underlying is set against the forward price/ rate used in valuing the option at expiration. This option has a positive intrinsic value with respect to the prevailing market forward rate. The option holder would exercise the option in order to capture its intrinsic value (economic value), and hence the option matures immediately.
A call option will have intrinsic value if the strike price is lower than the spot price. A put option will have intrinsic value if the strike price is higher than the spot price.
It is also known as ITM forward.
