Which market did the 1914 outbreak of World War I force to close for nearly four months?

The 1914 outbreak of World War I forced the New York Stock Exchange to close for nearly four months. Trading was suspended on July 31, 1914, as officials feared panic selling, disruption of international finance, and a rush to convert securities into cash.

The closure lasted until December 12, 1914, making it one of the longest interruptions in the exchange’s history. When trading resumed, the exchange used restrictions and other measures to manage disorderly conditions. The interruption also affected international securities markets and communications.

This episode is often described as a market closure rather than a conventional one-day crash. The outbreak of war created extraordinary uncertainty about trade, credit, currencies, and the solvency of financial institutions. Closing the exchange gave authorities time to limit forced sales and stabilize the financial system.

The exchange had reopened before the United States entered the war in 1917. Its experience in 1914 showed how geopolitical emergencies could interrupt market infrastructure itself, not merely cause prices to fall. Modern exchanges use circuit breakers and other controls, but temporary closures remain an emergency tool.