I'm not sure that's true this time around. We've allowed a lot of otherwise unhealthy companies to thrive, and have even allowed them to continue, in general, the unhealthy practices which got us all into this spot in the first place. We're getting rid of liar loans in the housing market (largely through the wholesome and healthy method of drying up credit almost completely), but we still have a derivatives bubble of between $500 trillion and $1.5 quadrillion.

Regarding stock price, "prolonged" is pretty relative, considering that we're trading over tens of milliseconds nowadays.