World War I forced the New York Stock Exchange to close for four months in 1914.
The exchange suspended trading on July 31, 1914, as the conflict created extreme uncertainty and threatened a rush to sell securities. The closure was also linked to concerns about gold outflows and the ability of international investors to settle transactions while European markets were disrupted.
The NYSE reopened on December 12, 1914, initially with restrictions designed to control trading and prevent disorderly selling. The closure was one of the longest interruptions in the exchange’s history and temporarily separated U.S. markets from the financial shock spreading across Europe.
This episode is often described as the 1914 stock-market crisis, but the underlying historical event was the outbreak of World War I after the assassination of Archduke Franz Ferdinand. The exchange’s closure was not itself a conventional one-day crash such as Black Monday in 1987; it was an emergency market shutdown during wartime.