Quote from dmo:
Exactly correct. Then once I get the implied volatility for the ATM options, I have a baseline against which I can compare other options to see if they are relatively "cheap" or "expensive."
I'm only interested in whether options are cheap or expensive compared to each other, not compared to the actual volatility of the underlying security. Not that it would be impossible to construct a strategy based on comparing IV to actual volatility, it's just very difficult because the volatility that matters is the volatility that WILL exist from now until expiration, and how do you know what that will be?
But if you do have reason to believe that future volatility will be different from existing volatility and - more to the point - from existing implied volatility, then that is certainly a legitimate play.
Many thanks. I'm curious do you trade equity options or futures options. if both, which is your major focus?