This is an options strategy which works when markets move in either direction up or down, in this strategy we by call option of higher strike price and put option of lower strike price of current value of the stock at the same time with almost same value.  When market rises call option value will increase at the same time put option value decrease but call option gives more profit. When market down put option value will increase at the same time call option value decrease but put option gives more profit. In range bound market this strategy will not work as it erodes premium of options. This strategy works better at the time of results or any big events.