Short Butterfly Spread

Reverses the standard butterfly: the two outer strikes are sold and two contracts at the middle strike are bought, all in one expiration, bringing in a net credit that is kept when the stock moves away from the body in either direction.

Maximum loss occurs at the middle strike and is limited to the strike width less the credit received. Each leg is priced from bid and ask so the credit is not overstated, and the payoff grid marks the breakeven on each side of the body.