Also, with a time spread, I think it’s been mentioned that part of the mispricing is due to retail traders predominantly using the cheaper weekly expiration to speculate on earnings instead of more expensive further-out options, so a disproportionate amount of earnings-related IV is packed into that nearest expiration options chain. I would also bet that FOMC related speculation is more evenly distributed among different options expiration dates than earnings related speculation, since people know that post-earnings moves often happen immediately overnight but post FOMC moves might take longer to materialize, so paying more in time-premium is worth it. If this is true, it would further reduce the edge of the time gap between the short-vega leg and the long-vega leg because the FOMC related IV is more spread out among different expiration dates. But that part is entirely just speculation and a total guess on my part and more relevant to a pure interest in options than actual trading.
October 5, 2022