why did the stock market crash in 1929

The stock market crash of 1929 happened mainly because of an extended period of speculation where many people invested or borrowed money to buy stocks, pushing their prices to unsustainable levels. This was coupled with other causes like an increase in interest rates by the Federal Reserve, a mild recession earlier that year, overproduction and underconsumption in agriculture and industry, and declining consumer purchasing power. Speculative buying on margin created a bubble as stock prices rose far above real value, and when confidence faltered due to economic weakness and political uncertainty, panic selling led to a rapid market collapse in late October 1929. The crash marked the start of the Great Depression, the most severe economic downturn in U.S. history.