A graphical curve that charts the implied volatility of a group of options, using either the same expiration date and various strike prices (more common), or across various dates with the same strike price. The curve shows that implied volatility is higher in either In The Money (ITM) options or Out Of The Money (OTM) options. Hence the demand will be higher in whichever end has more implied volatility. This curve is commonly seen in the longer-term options market.