Let’s try to keep productive and extractive to their economic meanings, and not talk about the exploitative practices with natural resources for a moment.

A farmer puts products that people buy into the marketplace. Many actors in the financial sector make their money by micro-timing trades in securities and commodities markets that are already liquid enough they don’t need the additional activity. Others buy up stock of housing just to control enough to raise the prices. They are literally just taking other people’s money out of the economy for their own gain, and the economy does not function any better due to their activity. In fact, when housing is overly tight the economy suffers.