How did speculation in the stock markets especially in the US help cause the global depression?

Speculation in the US stock markets during the late 1920s led to inflated stock prices, creating a bubble that eventually burst in 1929. Investors engaged in excessive buying on margin, which amplified losses when stock prices plummeted. This crash undermined consumer and business confidence, leading to reduced spending and investment. The resulting economic contraction contributed to the global depression, as interconnected economies faced declining trade and financial instability.