Important question [but it should be obvious...] I am joining ONE, but am hesitating due to the problem understanding the availability of historical prices... Is it possible to see actual option prices from earlier on the same day? Meaning, if I see an underlying reach 2500 at 9am, and then it drops and again touches 2500 at 2p, can I (at 2p) go back and see what option prices were for different strikes and expirations at 9am? This seems critically important and essential, but the description of "live feed" vs "historical prices" (especially the problem with seeing Friday's prices only after the market reopens on Monday morning) leaves me cold.... Thanks for any info.