Which U.S. index lost nearly 90% during the Wall Street Crash from 1929 to 1932?

The Dow Jones Industrial Average lost nearly 90 percent during the Wall Street Crash from 1929 to 1932.

The Dow reached a pre-crash peak of 381.17 on September 3, 1929. After the spectacular October sell-off, it continued falling through the early years of the Great Depression and eventually reached a low of 41.22 on July 8, 1932. The decline was therefore much longer than the dramatic trading days usually remembered as the crash.

The 1929 collapse followed years of strong speculation, widespread stock buying on margin, uneven economic conditions, and weakening industrial activity. Black Thursday, October 24, and Black Tuesday, October 29, became especially famous dates, but neither date alone represents the entire bear market.

The Dow did not regain its 1929 closing high until 1954. The crash helped intensify the Great Depression, although historians identify many interacting causes rather than a single trigger.