title: The Unified Model author: Keith A. Lewis institute: KALX, LLC classoption: fleqn fleqn: true abstract: Basic model. ...
\newcommand{\Var}{\operatorname{Var}} \newcommand{\cone}{\operatorname{cone}} \newcommand{\RR}{𝑹} \renewcommand{\AA}{\mathcal{A}}
One component missing from many mathematial finance models is an indication of who owns an instrument.
A holding is an amount, intrument, and entity. The triple