Which Wall Street index lost 89% from its 1929 peak to its 1932 low during the Great Depression crash?

The Dow Jones Industrial Average lost about 89 percent from its 1929 peak to its 1932 low during the Wall Street Crash and the ensuing Great Depression.

The Dow reached a closing high of 381.17 on September 3, 1929. It later fell to 41.22 on July 8, 1932, a collapse that erased almost nine-tenths of its value. The market’s decline was part of a much broader economic crisis involving bank failures, unemployment, deflation, and falling industrial production.

The crash itself unfolded over several dramatic sessions, including Black Thursday on October 24 and Black Tuesday on October 29, 1929. The market did not reach its ultimate low until nearly three years later.

The S&P 500 and Nasdaq Composite did not exist in their modern forms at that time. That is why the Dow is the canonical index for this widely cited historical statistic.