News analysis: Why prices are slippery on the way down

Foreclosures in 'exurbs' weigh on Case-Shiller indices

It used to be that when real estate markets went south, they did so in a somewhat leisurely fashion. Buyers stopped buying and builders stopped building, but prices would stagnate or get a little soft — not plummet overnight like the stock of some corporation that’s been flown into the side of a mountain.