From the Rulebook introduction:

Shrewd is a fast paces game where deal making, strategy, manipulation of other players, and a little luck, leads to success. the object of Shrewd is to maximize your own wealth, at the expense of your opponents. The player with the most money wins. The player increase their wealth in two ways.
First... by ARBITRAGE, which simply means: "gains made through buying and selling".
Second... by meeting the requirements for winning the monopoly fund, greed fund, shrewd fund or by winning one of the five equity finds.