The 9 May 1873 Vienna Stock Exchange crash was known as Black Friday. The collapse helped trigger the Panic of 1873, an international financial crisis that spread from Europe to the United States.
Vienna had experienced intense speculation during the economic expansion that followed the Austro-Prussian War. Share prices rose sharply, and investors poured money into newly formed companies and property ventures. When confidence broke, prices fell rapidly and many speculative enterprises failed.
The panic was not limited to a single exchange. Financial stress spread through Germany and Austria-Hungary, while the United States experienced its own major shock later in 1873. The crisis contributed to a prolonged period of deflation and weak growth often called the Long Depression.
Black Friday in this historical context should not be confused with the modern shopping term or with other market days using the same nickname. The Vienna event is specifically associated with 9 May 1873.