Which exchange's 1873 collapse helped begin the Long Depression and spread a stock-market crisis internationally?

The Vienna Stock Exchange's collapse in May 1873 helped begin the Long Depression and spread a financial crisis internationally.

A speculative boom had developed in Austria-Hungary, especially around railway and construction companies. On May 9, 1873, known as Black Friday in Vienna, share prices plunged after confidence broke. The crash exposed weak or speculative enterprises and damaged banks and investors.

Financial stress then spread beyond Austria-Hungary, contributing to the Panic of 1873 in Germany and the United States. The crisis was connected with excessive investment, credit expansion, falling prices, and international financial links. Historians debate the exact boundaries and causes of the Long Depression, but the Vienna crash is widely treated as a crucial opening event.

This episode should not be confused with the 1929 Wall Street crash or the Black Friday gold panic of 1869. “Black Friday” has been used for multiple financial events, so the location and year are essential to identifying the 1873 collapse.