In the financial world, a bubble is a period when the price of an asset—typically stocks, bonds or real estate—irrationally exceeds the asset’s intrinsic value. While this kind of irrationality can last for extended periods, it is considered a bubble only if it bursts and prices plummet as sellers frantically try to get out.

The terms “financial bubble,” “asset bubble,” “economic bubble,” “market bubble” and “speculative bubble” are used interchangeably and often shortened to simply “bubble.” “Crisis” and “mania” are sometimes used as well.