Which 1929 crash day saw the Dow Jones Industrial Average lose about 12.8%?

Black Monday was the 1929 crash day on which the Dow Jones Industrial Average lost about 12.8%.

The fall occurred on October 28, 1929, after intense selling pressure had already shaken Wall Street. The next session, October 29, became known as Black Tuesday and brought another severe decline. Together, the two days marked the most dramatic phase of the Wall Street Crash of 1929.

The crash followed a speculative boom in American shares during the 1920s. Many investors bought stocks with borrowed money, known as buying on margin. When prices dropped, margin calls forced additional selling, turning declines into a destructive feedback loop.

The Wall Street Crash did not single-handedly cause every feature of the Great Depression. Banking failures, falling demand, reduced international trade, and policy decisions also mattered. A common mistake is to call October 29 the only “Black” day; October 28 was Black Monday, while October 29 was Black Tuesday.