Markets generally do not exceed the upper or lower Bollinger band lines for long and gold needs to revert back to some equilibrium pricing.

FORBES: Technical Trading: Gold Prices Ripe for Consolidation near Term

Likewise, a well formed tight base on a stock that has slumped indicates that a re-pricing move has been completed and a new equilibrium has been reached.

FORBES: A No-Brainer Short-Term Apple Trade

Introduce a third seller, however, and the stifling equilibrium is broken as a series of market-energising relocations and pricing changes kick in.

ECONOMIST: Modelling behaviour