A type of quanto option whose value depends on the spot exchange rate at expiration date relative to a guaranteed level of exchange rate. At maturity, the dollar value of a joint quanto is given by:

MAX (FX_T, FX_G) x Max (0, S – X)

where: FX_T is the exchange rate at maturity, FX_G is the guaranteed exchange rate, S is the value of a foreign-currency-denominated asset, X is the option’s strike price.

The second expression, i.e., Max (0, S – X), captures the exposure to an unspecified amount of a given foreign currency.