Financial Sector
  
Back in the good ol’ days, we just traded everything. Barter this, barter that. But then along came money, as a representation of the barter value that was held in a beaver pelt and an ounce of gold and 14 eyes of newt. Cue the Financial Sector Era.
A broad-based infrastructure was needed to service, police, manage, and allocate the money that represented the value of those beaver pelts. And today with a deci-trillion dollar global economy (and Mars' MDP coming soon to a planet near you), we have banks and brokerages, insurance companies, accounting behemoths, and all kinds of corporations that service everything finance, everything money, everything representative of the value of a beaver pelt.
That's the Financial Sector. Live it; love it; pray to it, Earthlings.