After last Costco had a 14% down move. If we take into consideration last year, we have a CVPOC at around $150 Price, and in the shorter term the VPOC is around $167 (2017). That means that those prices are the ones that have traded the most and considered fair for the stock.
With an IV Rank at 67 we can sell some premium, so given the down move I sold a 3:1 Ratio spread for $1.66.
This gives us a max profit of $665 at the $150 level and if it stays above $155 price we would be making $166 at expiration.
Our probabilities of profit are very high at 86%
Sell (3) AUG18 155 PUT
Buy (1) AUG18 150 PUT
Hope that helps.
love your trades.