Greater fool theory
The greater fool theory states that the price of an object is determined not by its intrinsic value, but rather by irrational beliefs and expectations of market participants. A price can be justified by a rational buyer under the belief that another party is willing to pay an even higher price. In other words, one may pay a price that seems "foolishly" high because one may rationally have the expectation that the item can be resold to a "greater fool" later.