A "stock market bubble" refers to an economic exuberance (or extreme excitement) taking place in stock markets, in which a wave of enthusiasm for stock prospects causes an exaggerated bull market. When such a bubble takes place, market prices rise dramatically, making stocks overvalued. Generally stock market bubbles are followed by dramatic stock declines. A bubble can occur in the market in general or in particular industry sector. The 1999-2000 time frame saw the bursting of the "Internet Bubble."