XOM shows a fairly good example of a 7 Day Cycle - of which one could calibrate their options trades in respect to the overall move in 7 days. Take the IV Rank of the month option chain and multiply by 0.408 to get the "true" IV for that time frame. (Tastytrade provided the Volatility to Scaling formula: 7.5 days - IV*0.408) The FEB (22) Option Month shows a high Open Interest and Volume on the Put side at the Strike price of 85. Keep your eye on this and a possible reversal after this big sell off. The IV versus HV ranking signals a Short play.