Definitions for "At-the-Money Option"
Call and put option strikes that are nearest to the current price of the underlying. If the FTSE 100 is trading at 4,205 then the 4,200 calls and the 4,200 puts are deemed to be at-the-money. For the Traded Options guide click here
The option with the exercise price closest to the current price of the underlying instrument.
an option where the exercise price is the same as the market price of the underlying security