The U.S. stock exchange index central to the dot-com crash was the Nasdaq Composite.
The Nasdaq Composite peaked at 5,048.62 on March 10, 2000, after a spectacular rise in technology and internet shares. Investors had assigned very high valuations to companies whose business models and profits were often uncertain.
When confidence weakened, technology shares fell sharply. The Nasdaq Composite lost roughly 78% of its value from its 2000 peak to its October 2002 low. Many dot-com companies failed, while established technology firms also experienced substantial declines.
The index measures thousands of common stocks listed on the Nasdaq exchange and is heavily influenced by technology companies, although it is not exclusively a technology index. The dot-com crash is sometimes confused with the broader 2000–2002 bear market, which affected multiple sectors and indexes.