For nearly a decade, interest from the US Federal Reserve was 0%. So banks (and I think hedge-funds...?) could take out a no interest loan from the FR, then turn around and loan that same money to people with interest. As best I understand it, this is how a lot of those no-profit tech companies, like Netflix and Uber, were able to meet expenses. Banks and investors had the liquidity to throw around, and did so with reckless abandon.