Answer:
I would say stock prices being higher than their real value
Explanation:
A bubble is an economic cycle characterized by the rapid escalation of asset prices followed by a contraction. It is created by a surge in asset prices unwarranted by the fundamentals of the asset and driven by exuberant market behavior.
Bubbles in equities markets and economies cause resources to be transferred to areas of rapid growth. At the end of a bubble, resources are moved again, causing prices to deflate.
