The speculative bubble whose collapse caused major technology-stock losses around 2000 was the dot-com bubble.
The bubble formed during the late 1990s as investors poured money into internet-related companies. Many firms had little revenue, no profits, or business models dependent on rapid future growth, yet their share prices rose dramatically. The Nasdaq Composite reached a peak of 5,048.62 on March 10, 2000.
The market then reversed. Rising interest rates, disappointing earnings, and skepticism about internet valuations triggered a prolonged decline. The Nasdaq lost roughly 78% of its value from its 2000 peak to its October 2002 low.
The collapse did not mean that the internet lacked economic importance. Companies with durable technology, strong customers, and sustainable revenue eventually became successful. The common mistake is to equate the bubble with the internet itself; the bubble concerned excessive valuations and speculation around many internet businesses.