What market bubble burst when the Nasdaq Composite began its major fall in 2000?

The market bubble that burst as the Nasdaq Composite began its major fall in 2000 was the dot-com bubble.

During the late 1990s, investors poured money into internet and technology companies, many of which had little revenue or no profits. The rapid spread of the World Wide Web encouraged expectations that online businesses would transform commerce and justify exceptionally high share prices.

The Nasdaq Composite reached an intraday peak of 5,132.52 on March 10, 2000. Valuations then began to reverse as investors questioned whether many internet companies could generate sustainable earnings. The index fell for the next several years, and numerous dot-com firms failed or were acquired.

The bubble’s collapse is often confused with the later 2007–2009 financial crisis. The dot-com crash centered on technology and internet-stock valuations, whereas the later crisis was driven largely by housing finance, mortgage securities, and banking-system stress.