Assuming an average flow rate of about 1.5 million homes per year, you can eyeball the stock deficit by comparing the mass above and below the zero on the following graph.

FORBES: Are There Too Many Homes in America, Ctd

They should examine rate of flow, average time between orders, balance between buy and sell orders, and order sizes, to determine whether the order flow has become anomalous.

FORBES: After the Knight Capital Catastrophe, Throttle the Traders, Not the Markets

Most of it went in 90 minutes, at a rate that at its maximum was faster than the average flow of the Niagara Falls.

ECONOMIST: A meltdown tinged with acid

The economy actually contracted at a 1.3% average rate in 2008 and 2009, and this drove Social Security into a negative cash flow position in 2010, much earlier than the Trustees had ever imagined was possible.

FORBES: Social Security Needs Growth, Not Cuts