The dot-com boom of the late 1990s is one example. The biotech boom in the 1980s is another. Still other examples of stock market bubbles include Japanese stocks in the late-1980s, Nifty 50 stocks in the early 1970s, and Taiwanese stocks in 1987. A stock market bubble may set the stage for a later stock market crash, continuing our example, the Stock Market Crash of 2002.
See also:
Accounts of the South Sea Bubble, John Law and the Mississippi scheme, and the tulipomania can be read in Charles MacKay's classic "Extraordinary Popular Delusions and the Madness of Crowds'' (1841) - available for free download from Project Gutenberg.