A four-legged option trading strategy that involves buying a back-month out-of-the-money put option with the lowest strike price, selling a front-month, out-of-the-money put option with a higher price, selling a front-month, out-of-the-money call option with even a higher strike price, and buying a back-month, out-of-the-money call option with the highest strike price, all on the same underlying. The underlying price would generally be expected to remain in the range bounded by the strikes of the short put and the short call.

Differently looked at, this strategy is a combination of a diagonal call spread and a diagonal put spread which both play on time decay. That means an investor pursuing such a strategy will take advantage of the situation where the time values of the front month options diminish at a faster rate than the back-month options.