Currency Option Theta

Theta
Theta (T), also known as time decay, occurs as the very slow or nonexistent movement of the currency triggers losses in the option's theoretical value.
For instance, a theta of 0.02 will generate a loss of 0.02 in the premium for each day that the currency price is flat. Intrinsic value is not affected by time, but extrinsic value is. Time decay accelerates as the option approaches expiration, since the number of possible outcomes is continuously reduced as the time passes.
Time has its maximum impact on at-the-money options and its minimum effect on in-the-money options. Time's effect on out-of-the-money options occurs somewhere within that range. Bid-offer spreads in the market may make it too expensive to sell the option and trade forward out rights. If the option shifts deeply into the money, the interest rate differential gained by early exercise may exceed the value of the option.
If the option amount is small or the expiration is close and the option value only consists of the intrinsic value, it may be better to use the early exercise.
Due to the complexity of its determining factors, option pricing is difficult. In the absence of option pricing models, option trading is nothing but inefficient gambling.
The one idea to make option pricing is that the option of buying the domestic currency with a foreign currency at a certain price x is equivalent to the option of selling the foreign currency with the domestic currency at the same price x. Therefore, the call option in the domestic currency becomes the put option in the other, and vice versa.

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Currency Options

Currency Option Delta

Currency Option Gamma

Currency Option Vega

Currency Option Theta