Specifies how the underlying price is determined at the point of option exercise. The underlying price may be set to the current settlement price, set to a special reference, set to the optimal value of the underlying during the defined period ("Look-back") or set to the average value of the underlying during the defined period ("Asian option").
Valid values:
| '1' | Regular |
| '2' | Special reference |
| '3' | Optimal value (Lookback) |
| '4' | Average value (Asian option) |
Used in: