Hyman Minsky theory

The New Yorker: The Minsky Moment.

"There are basically five stages in Minsky’s model of the credit cycle: displacement, boom, euphoria, profit taking, and panic. A displacement occurs when investors get excited about something—an invention, such as the Internet, or a war, or an abrupt change of economic policy. The current cycle began in 2003, with the Fed chief Alan Greenspan’s decision to reduce short-term interest rates to one per cent, and an unexpected influx of foreign money, particularly Chinese money, into U.S. Treasury bonds. With the cost of borrowing—mortgage rates, in particular—at historic lows, a speculative real-estate boom quickly developed that was much bigger, in terms of over-all valuation, than the previous bubble in technology stocks."

Seeking Alpha: Introducing the Minsky Theory - Stability Is Destabilizing .