|Interestingly I came here with similar questions, though with a shorter timeframe.|
I was looking today at dec DIA calls vs. puts- at the time DIA was around 97.7 and the bid/ask of 97 puts and 98 calls was *identical*. Huh? the 98 calls were .3 OTM while the 97 puts were .7. Same price?
I also came hoping to get answers to another question- how is it that options pricing can vary drastically from a few hours earlier when the underlying returns to the same price? Today for example I bought calls at the bid 1.25- underlying price fell then returned back 2 hours later. Price was now ASK 1.1 ! Cant make any $ trading options till I can make sense of this.