Which U.S. stock index lost about 78% of its value during the 2000–2002 dot-com crash?

The Nasdaq Composite lost about 78% of its value during the 2000–2002 dot-com crash.

The index peaked at 5,048.62 on March 10, 2000, after years of rapid growth in technology and internet shares. It then fell to 1,114.11 on October 9, 2002, a decline of roughly 78% from the peak.

The Nasdaq Composite tracks thousands of stocks listed on the Nasdaq exchange and is heavily associated with technology companies. Because the dot-com boom concentrated many highly valued technology businesses in the index, it suffered a much larger percentage decline than broader market measures.

The index’s collapse is often confused with the performance of the Nasdaq exchange itself or with the Nasdaq-100, a different index containing 100 large non-financial Nasdaq-listed companies. The Composite’s 78% loss describes the movement from its 2000 peak to its 2002 low, not a single trading day.