The outbreak of the 1929 Great Crisis of the Dow Jones Index in the United States. In the eighteen months before October 29, 1929, the Wall Street stock market experienced an unprecedented crazy rise. The prices of some major industrial stocks actually It more than doubled, with daily trading volume at that time reaching 5 million shares. As investors poured money into the stock market, some funds also hurriedly withdrew from less profitable investment areas and turned to the stock market. European funds also poured into the United States. The craziest thing was that the U.S. banking industry actually lent a huge amount of about $8 billion to securities firms, accounting for 8% of the U.S. GNP at the time. A sharp rise will inevitably lead to a sharp fall, especially for an over-speculative market. The New York Dow Jones Index reached its all-time high of 419 points on September 3, 1929, with more than 8 million shares traded that day. But then the stock market began to fall, falling by an average of 18 points a day, hitting its first bottom on October 24, with 12 million transactions taking place that day. At this point, a coalition of banks moved quickly to control the situation, once again flooding the market with money. The shortcomings of the mixed banking-securities industry were quickly exposed. As the banks' self-operated stocks and the stocks purchased by customers using bank loans shrank significantly, banks had to significantly increase deposit interest rates to attract funds to save themselves. At that time, there were many banks that raised annual deposit interest rates to astonishing levels of 20%-30%. Although this could relieve financial pressure in a short period of time, it was nothing more than drinking poison to quench thirst. The stock price soon began to fall ruthlessly again. By October 29, it even plummeted by 40%. The prices of some major stocks shrank by more than 2/3. In the first month of the stock market crash, US$26 billion was wiped out. But this was only the first terrible blow to the stock market during the Great Depression, which was followed by four consecutive years of great bear markets. It was not until 1933 that this bear market finally reached the bottom at 37 points.