is it the famous ID xiaxie? the one with story of microwave?
c**********6 发帖数: 18
5
There are usually two reasons. One is vol skew. If it's sticky moneyness,
vol comes down along the vol surface as the stock price increases. The other
reason people usually call it leverage effect, ATM vol would also decrease
as the stock decreases. One explanation is the equity/debt ratio decrease as
the stock price decreases such that the company assumes more risk .
