Payoff__Payoff_Type__Vanilla

In the call case the payoff equals the amount by which the referenced variable *x* exceeds some fixed strike *K*

The payoff is zero if *x* falls below *K*

In the put case, everything is reversed so that *x* must fall below *K* for a payoff to occur.

The formal definition is as follows:

*x* is transformed into *max{ ε(x-K) , 0 }* where *ε* and *K* are constants defined in the contract specification.

Furthermore *ε* can take only the values *1* or *-1* and corresponds to a payoff attribute called Payoff::Direction

*K* may take any value and is usually referred to as "strike".