No reason to do anything as complicated as a calendar spread. Just do a single option; if it holds for one option, it will hold true for any combination of options.Quote from nitro:
Well, I am not saying it would prove something or nothing. You claim you would be "...profitable if realized volatility was less than IV, and a loser if realized volatility was higher than IV." Ok, let's see if that is all it requires. We will have a measure of IV and realized at each hedge. We can wave our hands in the air all day long, but nothing beats a real-world test, even if that test is humble.
We'll just do something simple. SPY (closed 116.58). I'll use SamoaSky's OptionOracle for simple pricing.
Let's pretend Friday afternoon I sold 10 contract of the 117 Apr10 call, trading at 1.50/1.52. Premium: $1500.
Delta (according to OptionOracle) 46.82. I go long 468 contracts of SPY, and I'm delta hedged. Cost: -$54559.
Cash account: -$53059.44.
Theta (with current IV of 15.44%) is -4.15; if underlying doesn't move, I would be out ~$124.50 on the option position by Monday afternoon.