This is another one of those books that follows the lives of the billionaires -- this time the Hunt family. At some point, the money is just a what is known as a "numeraire" -- it has no significance except as a number. And it is merely the number that the Hunt's go after in their effort to capture the silver market.
Most of Marx's insights about capitalism can be seen in this story -- by no means is Fay (they author) a marxist, though.
My friend Paul once told me that the true sign of wealth is not how much you have but how much dept you can accrue. At one point, one of the Hunts is so far in debt that the US government fears a collapse of a segment of the economy. It thereby bails out Hunt and his debt.