Consider a non-liquid option market with a wide bid-ask spreads across all strikes. Spot: $52 A snapshot of the $50 strike shows: Bid - Ask Call: 2 - 4.5 Put: 0.5 - 3.5 Assume 0% interest. Is there a set of rules or a model that could minimize the range of possible IV's by entering the option's bid/ask prices? because these options have a very wide spread and their last price changes sporadically i cannot achieve one appropriate fair value/IV for each option, and as i have mentioned, it's applies to all strikes and therefore i'm incapable of forming a skew. so my question is if there's a math way to obtain min&max fair value outcomes for each option?