From the Bubble of American Supremacy | George Soros: "Bubbles do not grow out of thin air. They have a basis in reality—but reality as distorted by a misconception. Under normal conditions misconceptions are self-correcting, and the markets tend toward some kind of equilibrium. Occasionally, a misconception is reinforced by a trend prevailing in reality, and that is when a boom-bust process gets under way. Eventually the gap between reality and its false interpretation becomes unsustainable, and the bubble bursts.

Exactly when the boom-bust process enters far-from-equilibrium territory can be established only in retrospect. During the self-reinforcing phase participants are under the spell of the prevailing bias. Events seem to confirm their beliefs, strengthening their misconceptions. This widens the gap and sets the stage for a moment of truth and an eventual reversal. When that reversal comes, it is liable to have devastating consequences. This course of events seems to have an inexorable quality, but a boom-bust process can be aborted at any stage, and the adverse effects can be reduced or avoided altogether. Few bubbles reach the extremes of the information-technology boom that ended in 2000. The sooner the process is aborted, the better."