The stock-market index most associated with the bursting of the dot-com bubble in March 2000 was the Nasdaq Composite.
The Nasdaq Composite rose rapidly during the late-1990s technology boom because it included many internet and technology companies. Investors often valued firms on expected future growth rather than current profits, and venture capital funded a large wave of new online businesses.
The index reached a record closing level of 5,048.62 on March 10, 2000. It then fell sharply as investors questioned unrealistic valuations and many companies failed to produce sustainable earnings. The decline continued for years, and numerous dot-com firms went bankrupt or were acquired.
The Nasdaq Composite was not the only index affected: the S&P 500 and other markets also declined. However, its concentration of technology shares made it the clearest market barometer of the bubble and its collapse.