The largest one-day percentage gain in the Dow Jones Industrial Average was 15.34%, recorded on March 15, 1933. The rise occurred during a dramatic period of financial stress in the United States, near the end of the banking crisis associated with the Great Depression.
The gain followed the nationwide bank holiday declared by President Franklin D. Roosevelt earlier in March. The temporary closure was intended to stop bank runs and give regulators time to assess banks before reopening them. News that banks would reopen under new restrictions helped improve market confidence.
The Dow’s percentage gain is distinct from its largest point gain. Percentage records are especially useful when comparing eras because the index’s numerical level has changed greatly over time. A move of a given number of points has a very different meaning at different index levels.
The March 15, 1933, record has remained a historical benchmark rather than a typical trading-day movement. It is separate from the record percentage losses associated with the 1929 and 1987 crashes.