From the instruction book:
"hot money... Will you be a saint or sinner?
The object of the game is to become the first player to reach THE TOP. To get there you must make millions of $$$, run up hundreds of thousands in debt, and earn a glowing reputation while surviving all the dirty tricks and delaying tactics your opponents play against you.
There are two levels of play:
The Daily Grind (the outer board) where you must earn your fortune in Cold Cash and/or in Hot Money.
and
High Society (the inner board) where you earn your reputation by purchasing the Keys to Success"
Hot Money is a roll and move game that uses two currencies, cold cash and hot money. Hot money comes from various illicit activities, and must be laundered into cold cash before a player can enter High Society