The Nasdaq Composite's peak closing value during the dot-com crash era was 5,048.62.
The index reached that closing record on March 10, 2000, near the end of the dot-com bubble. Investors had bid up internet and technology companies, sometimes despite little revenue, no profits, or business models that had not been tested at scale.
After the peak, the Nasdaq fell for roughly two years. By October 2002, it had lost about 78% from its high. The collapse damaged technology companies, venture-capital portfolios, and many retail investors, while a smaller group of established firms eventually became major businesses.
The number is a closing value, not the highest intraday level. The Nasdaq Composite also differs from the Nasdaq-100, a separate index of large nonfinancial companies. These distinctions explain why different sources may quote other peak figures when discussing the same period.