http://en.wikipedia.org/wiki/Kondratiev_wave
and wondering to what extent we are seeing credit financing the creation of new waves of technology to give the upswing followed by periods of repayment of the debt (and hence monetary contraction in a deficit-based monetary system) from the revenues from the new generation of productive assets, on the downswing.
So cycles - bounded by the mathematics of compound interest on the money supply - would be intrinsic to our current - deficit-based - form of Capitalism. "Any economic unit can emit money. The serious problem is to get it accepted" Hyman Minsky
As to the severity and character of the cycles, sure. "It's the statue, man, The Statue."
In particular, experienced stock traders are surely aware of Ponzi modes in one way or other. Taking benefit from that must be a usual buisiness for them. Predicting moods of new market players is even an easier task than estimating "intrinsic" value of companies. (This is akin to the job of bookmakers: they do not really predict sport events; they just have to predict moods of participating betters. If they force bets to be distributed evenly, bookmakers win their daily bread with any outcome of the sport event.)
