BlackScholes calculations are quite complex and dependent on many input factors. For that reason, there are new settings in the Preferences, where you can set the basic input parameters which TradersYard X should use for the greeks-calculations for IQ-Feed. If you do not have deep knowledge about the BlackScholes formula, we recommend that you do not change the values provided by default. The values calculated by the BlackScholes formula also have some estimations in it, as BlackScholes is basically calculating greeks for European style options, while today most options are American style options. Greeks are a complex topic, and you most probably will get different results for greeks and implied volatility for every single source you check. Anyway, we try to calculate the greeks in the most efficient and best possible way.