An option that can be exercised at different times during the life of the option. The various times set for exercise are written within the option and allow for flexibility for both the writer and holder of the option.
The Mid-Atlantic option is named as such because its exercise dates are more flexible than European options and less flexible than American options. Thus, it is in the middle, just like the Atlantic Ocean is between Europe and America. Mid-Atlantic options are also referred to as Bermuda, Quasi American, or Semi-American options.