Which was a cause of the 1929 stock market crash?

One significant cause of the 1929 Stock Market crash was rampant speculation, where investors purchased stocks on margin, borrowing money to buy more shares than they could afford. This created an unsustainable bubble as stock prices soared beyond the actual value of companies. Additionally, a lack of regulatory oversight and economic instability contributed to the crash when panic selling began in late October 1929, leading to a significant market collapse.