Which technology-heavy US index reached its dot-com-era closing peak on 10 March 2000?

The technology-heavy US index that reached its dot-com-era closing peak on 10 March 2000 was the Nasdaq Composite.

The Nasdaq Composite climbed rapidly during the late-1990s dot-com bubble as investors bought internet, software, and telecommunications companies. Many firms had little revenue or no profits, but expectations about future online business drove their valuations higher. The index closed at 5,048.62 on 10 March 2000.

After that peak, technology shares fell sharply. The downturn spread through venture capital, telecommunications, and internet businesses, and many start-ups failed. The Nasdaq’s decline became the clearest market symbol of the dot-com crash, although other indexes and companies were affected too.

The Nasdaq Composite is not the same as the Nasdaq-100. The Composite includes thousands of Nasdaq-listed common stocks, while the Nasdaq-100 tracks 100 large non-financial companies listed on the exchange. That distinction matters when comparing historical peak figures.