The virtuous circle refers to a complex chain of positive events that reinforce themselves through a feedback loop. A virtuous circle has favorable results, while the opposite, a vicious circle, has detrimental results.
Both circles are complex chains of events with no tendency toward equilibrium (social, economic, ecological, etc.) — at least in the short run. Both systems of events have feedback loops in which each iteration of the cycle reinforces the previous one (positive feedback). These cycles will continue in the direction of their momentum until an external factor intervenes and breaks the cycle.
A well-known example of a vicious circle in economics is hyperinflation. The subprime mortgage crisis of 2008 was an excellent example of the end results of a vicious circle.
In contrast, an Investment Fund based upon a large Token Economy is a prime example of a virtuous circle.