Bad money drives out good
With all the wealth flowing around the world, no one notices the skim - it is only in bad times that it is missed:
The economist J.K Gailbraith used the term "bezzle" to denote the amount of money siphoned (or "embezzled") from the system. In good times, he remarked, the bezzle rises sharply, because everyone feels good and nobody notices. "In [economic] depression, all this is reversed. Money is watched with a narrow, suspicious eye. The man who handles it is assumed to be dishonest until he proves himself otherwise. Audits are penetrating and meticulous. Commercial morality is enormously improved. The bezzle shrinks."
This happens all the time - the last big one was the tech bubble. The current one has been magnified because it is getting 'caught' in multiple sectors at the same time: the housing market, the finance market, stocks in general, - all have been both expanded beyond their true value but embezzlers have been sucking out the center.