The ratio of stock market value to GDP generally reflects the level of securitization in a country's economy, which not only depends on the number of stocks listed and the changes of market value, but also on the scale of GDP. According to statistics, there are 4,906 listed companies on the US capital market with a total market value of US$47 trillion, of which the New York Stock Exchange is US$28 trillion and Nasdaq is US$19 trillion. The US GDP in 2019 is US$21 trillion, and the ratio of the total market value /GDP of the US stock market is 224%. There are 3,938 A-share listed companies in China, with a total market value of 73.8 trillion yuan. In 2019, China's GDP is 99 trillion yuan, and the ratio of total market value to GDP is 75%. However, it should also be noted that there are still many companies listed in Hong Kong and the United States, namely Chinese Hong Kong shares and overseas Chinese concept shares. The total market value of these overseas listed Chinese shares accounts for about one-third of the total market value of the mainland, which is about 25 trillion yuan. If this is added, the ratio of the total market value /GDP of China's stock market is close to 100%. The ratio of the total market value /GDP varies from country to country. The ratio generally reaches 100% in the moderately developed countries and above. Some analysts pointed out that the ratio of the total market value of the stock market to GDP of that year roughly reflects the overvaluation and undervaluation of the stock market, and the more reasonable ratio should be around 120%.