describing (with clarity) the complexity of vol fitter

Highlight complexity only after you achieve clarity.

* First focus on a simple smile curve with 3 points. Assume exchange sends you implied vol (no need to explain what IV is)
* Then 2 smile curves forming a 3D surface.

* explain curve fitting on one smile curve -- many technical people can understand it
** fitting is important because raw data could be inconsistent and invalid.
** explain fitting cost
* talk about term structure of vol
* talk about term structure of curve parameters
* mention dynamic nature of the surface -- previous surface as a first guess
* describe extrapolation -- important for many structured deals
* mention skew parameter on the parametric form
* mention smoothness
* mention surface models -- cubic, orthogonal
* describe inversion outliers -- to be removed during inversion, before fitting.