Which European exchange's 1873 collapse helped spread the Panic of 1873 from Austria across international markets?

The Vienna Stock Exchange's collapse helped spread the Panic of 1873 from Austria across international markets.

A speculative boom had developed in Austria-Hungary after the Austro-Hungarian Compromise of 1867 and ahead of the 1873 Vienna World's Fair. Banks and companies expanded rapidly, and share prices rose amid optimism about railways, construction, and economic modernization.

On May 9, 1873, confidence broke in Vienna. A wave of selling and failures among banks and companies became known as the Gründerkrach, or founders' crash. Financial stress soon crossed borders, contributing to panic in Germany and later the United States, where Jay Cooke and Company failed in September.

The Panic of 1873 is often dated from the U.S. railroad-financing crisis, but Vienna's stock-market crash was an important earlier international shock. The resulting long slowdown is sometimes called the Long Depression.