Twenty-seven years ago today, on March 18, 1998 (February 20, 1998 lunar calendar), the second and third largest stock exchanges in the United States merged. On March 18, 1998, the Nask Exchange, the second largest stock exchange in the United States, and the American Stock Exchange, the third largest stock exchange in the United States, announced a preliminary agreement to merge. The financial community saw this move as a blow to the leading position of the New York Stock Exchange. Compared with the New York Stock Exchange, which has a history of more than 200 years, the two exchanges are relatively small. Therefore, the two sides decided to learn from each other's strengths and weaknesses in a joint way in order to strengthen their competitiveness as soon as possible. Once the plan is successful, the two sides will merge into a holding company, but the operation will still be temporarily separated. According to the expectations of the two exchanges, the merger will bring the following benefits: First, it will reduce operating costs. Second, it will increase the attractiveness of listed companies. At present, the Nasdaq Stock Exchange is the only exchange in the world other than the London Stock Exchange that uses electronic operation, while the US bourse still uses traditional outcry trading. After the merger of the two, the trading method will be freely chosen by the listed companies. Third, most of the listed companies on the US bourse are small companies, and Nasdaq can gain momentum after joining. Fourth, it can stabilize the military heart and prevent the big companies that have already listed from "jumping ship". The big companies such as Microsoft and Intel, which are listed on the Nasdaq, have been the targets of the New York Stock Exchange. The merged exchange will retain them with stronger strength and good development prospects. Fifth, options trading on US bourse is unique in the New York area, and when combined with Nasdaq, the business can play a greater advantage. Judging from the current strength of the three exchanges, the total market capitalization of listed companies on the New York Stock Exchange is the largest, reaching 11.20 trillion US dollars, Nasdaq and US bourse are 1.80 trillion US dollars and 162 billion US dollars respectively. However, in terms of the number of listed companies and the average daily trading volume, the Nasdaq Stock Exchange is the largest. As of the end of last year, there were 5,487 companies listed, with an average daily trading volume of 648 million shares; while there are only 3,046 listed companies on the New York Stock Exchange, with an average daily trading volume of 530 million shares. There are 783 listed companies in the US bourse, with an average daily trading volume of 28 million shares. Therefore, what kind of weather the merger will bring to the New York stock market has become the focus of the financial community. It is reported that the US securities regulator has now expressed support for the merger of the two exchanges. Soon, shareholders of the two stock exchanges will also vote on whether to merge.