Implied Volatility Parameters for Underlying Instruments
If the instrument in the active chart window is an underlying instrument, the Implied Volatility parameters menu changes. First, since the underlying instrument is in the chart, the Underlying record disappears. In its place, the parameters menu creates an Ivol Type record and an Option Root record:
Ivol Type Specifies the type of Implied Volatility graph you want. Your choices are listed in the Ivol Type menu:
In this menu, selections that are followed by a plus sign (+) indicate just
above the money, and selections that are followed by a minus sign (-) indicate
just below the money.
Option Root The symbol root of the option against which the stock’s implied volatility is evaluated.