IBM has earnings (after close) on July 18th.
Currently it is trading around 157.50.
The July 22 157.50 straddle is trading at around 6.75, anticipating a 6.75 move after earnings.
The July 22 /Aug monthly calendars from 155 through 165 are trading around .40 - .45 cents..... .50 cents at worst
If you did some form of triple calendar (155-160-165) , the p/l chart shows a range of profitability from 150 - 170.
With a maximum gain of 5.00 and maximum loss of 1.35
You are selling 31 IV and buying 20 IV