As I was watching an Options Video on Tastytrade's website, I discovered that IV Percentile on ThinkorSwim is really the same as IV Rank on tastytrade. What is IV Rank and IV Percentile? You can check out the video here from tastytrade: https://www.tastytrade.com/shows/the-skinny-on-options-data-science/episodes/iv-rank-and-iv-percentile-w-thinkscript-11-12-2015 I use IV Rank to determine when to sell and when to sell Options. For instance: IV Rank < 50% Action To Take : Buy Option Why? : Option Premium Cheaper, so we Buy Low and Sell High IV Rank > 50% Action To Take : Sell Option Why? : Option Premium Expensive, so we Sell High and Buy Back Low Since on ThinkOrSwim, the IVPercentile is the same as IVRank you can find the IV Percentile in the Trade tab under Today's Options Statistics : This is just a general rule of thumb but if the IV Rank falls within the above range, the probability of success to make money is higher. I use this determine when to sell and wh...