Which U.S. stock index first entered a bear market during the 2000–2002 dot-com crash?

The Nasdaq Composite was the U.S. stock index most directly associated with entering a bear market first during the 2000–2002 dot-com crash.

The Nasdaq was heavily weighted toward technology, telecommunications, and internet companies, the sectors most affected by the collapse of speculative valuations. It fell into bear-market territory after dropping at least 20% from its March 2000 peak, while many individual technology shares had already lost far more.

The downturn later spread broadly. The S&P 500 and Dow Jones Industrial Average also suffered substantial declines as corporate profits weakened, technology investment slowed, and accounting scandals damaged investor confidence. The Nasdaq eventually reached a low in October 2002.

“Bear market” is a formal market term generally meaning a decline of at least 20% from a recent high, although exact definitions can vary by source. The Nasdaq’s concentration made it both the clearest indicator of the bubble and the index most exposed when expectations reversed.