The Nasdaq Composite fell about 78% from its March 2000 peak during the dot-com crash.
The Nasdaq Composite was heavily weighted toward technology and internet companies, many of which had little revenue or no profits. Investors nevertheless bid up their shares because they expected rapid growth from the emerging commercial internet.
The index reached an intraday high of 5,132.52 on March 10, 2000. As expectations changed, investors sold speculative companies, venture funding dried up, and numerous internet businesses failed. The Nasdaq ultimately lost roughly 78 percent of its value before reaching its low in October 2002.
The crash did not mean that the internet lacked economic importance. Companies with stronger business models eventually became major firms, while many speculative ventures disappeared. The Nasdaq is often confused with the broader S&P 500, but its technology concentration made it the clearest benchmark for the dot-com collapse.