There were several main causes of the Great Depression:

• Overproduction and overcapacity: Many industries, particularly in the manufacturing sector, had been producing at an unsustainable level, leading to a surplus of goods and a decline in prices. This made it difficult for businesses to turn a profit, leading to a decrease in investment and hiring.
• Stock market speculation: The stock market had been on a bull run in the late 1920s, with prices reaching unsustainable levels. When the market began to decline in 1929, it triggered a panic, as people rushed to sell their stocks. This led to a collapse in stock prices and a reduction in wealth, which further exacerbated the economic downturn.
• Bank failures: Many banks had invested heavily in the stock market, and when stock prices collapsed, they were left with large losses. This led to a wave of bank failures, which exacerbated the economic downturn and reduced the availability of credit.
• International trade: The depression was exacerbated by a decline in international trade, as countries imposed tariffs and other trade barriers in an attempt to protect their domestic industries. This led to a further decline in global economic activity.