Hi everyone, I'm looking at Orc Trader but am not very sure about certain features, please see the attached jpg file: (Mainly concerned about the lower part of the picture) 1. What does the green vertical line mean? Seems to me that it is about ATM volatility? 2. What does the green curve stand for? I can see that the x-axis is about price but not sure what does the curve stand for. 3. What do the blue and red triangles stand for? Could it be buy/sell of the option? But as this screenshot is about volatility trading, I'm not sure if it is the case as I know nothing about it. Thanks a lot!