A high PE for a growth stock is around 40 and thats a 1 year target PE. AMZN has good growth potential, but not enough to justify a 70. Shorts can think of many other companies with a better value then AMZN and more growth potential. AMZN usually trades with tech market and every tech stock that has posted good Q3 numbers has popped less then 15% and dropped at least 5%. AMZN popped 25% and gave back 2%. If you go with the charts, AMZN is do for a correction. No shorts thinks this company is worthless. They just believe the current valuation does not justify the price.
But shorting a growth stock when it's heavily owned by the funds and bigboys is going against the house, a losing propostion. amzn does not go down because retail shorts think the pe is too high. it just doesn't. You'd know that if you saw how it trades. so many clueless retail shorts.