The May 9, 1873 stock-market collapse in Vienna is known as Black Friday and helped begin the Long Depression.
On May 9, 1873, the Vienna Stock Exchange suffered a severe collapse after years of speculative investment, especially in property and railway companies. The event followed the boom associated with Austria-Hungary’s economic expansion and the 1873 Vienna World’s Fair. Panic selling exposed weak companies and damaged confidence in financial markets.
The shock was part of a wider international downturn. Banking failures and market declines spread through Germany, Austria-Hungary, and later the United States. In the United States, the failure of Jay Cooke & Company in September 1873 contributed to a banking panic and the closure of the New York Stock Exchange for several days.
Black Friday here is not the famous shopping day or the 1869 U.S. gold panic. It refers specifically to Vienna’s 1873 crash. The resulting long period of weak growth is commonly called the Long Depression.