Because there is no short-selling mechanism in China stock market, in the case of a stock market crash, each investor can only cut his position or make his assets shrink sharply; Since China has joined the WTO, the securities market must be open to the outside world and be in line with foreign countries. Recently, the voice of share price index futures is getting louder and louder. The influence of stock index futures can be roughly divided into the following categories: 1. Some people think that because of the prevalence of speculation in China stock market, it is difficult to quickly change the speculative psychological tendency after the introduction of stock index futures, and shorting stock index futures will aggravate stock index volatility. However, a large number of empirical studies abroad show that the existence of stock index futures usually does not increase the fluctuation of stock index. The reason why the fluctuation of stock index is sometimes increased is that stock index futures have the function of price discovery, which can improve the reflection mode of spot market to market information. Some people also worry that the stock index may fluctuate abnormally on the maturity date. The statistical analysis of Hong Kong Futures Exchange shows that there is no significant difference between the volatility of stock index futures with term and without term. 2. Impact on the liquidity of the stock market. The initial opening of stock index futures in emerging markets will often have a transaction transfer effect, that is, attracting funds from the stock market to the stock index futures market, which will greatly reduce the stock market transactions and liquidity. This happened to the Japanese when they first came to share price index futures. However, there is another function of stock index futures, which is to attract off-exchange funds. As stock index futures provide investors with a tool to avoid risks and expand their choice space, share price index futures trading will attract a large number of off-site wait-and-see funds to substantially intervene in the stock market, and in addition, it can reduce the accumulation of funds in the primary market. Therefore, the impact on stock market liquidity depends on the relative size of the two effects. The situation in the United States is that after the opening of stock index futures trading, the trading volume of stock market and futures market has been greatly improved, showing a two-way promotion trend. Judging from China's situation, because large institutional investors such as open-end funds, social security funds and insurance funds do not participate in or only partially participate in the stock market, and the increasing bank deposits, OTC funds can be described as huge. Therefore, the author believes that the introduction of stock index futures in China is expected to increase market liquidity. 3. Impact on market structure and operation concept After the introduction of unified index and stock index futures, the market structure and investment concept will undergo new changes. First of all, on this basis, we can further create new financial instruments, such as index funds and futures options. Three years after the Kansas Futures Exchange introduced the value line index futures on 1982, the compound index fund appeared in the United States. Secondly, China's traditional banker's stock trading mode may change slowly, and the value investment concept based on hedging will get more recognition and practice. 4. Impact on brokerage business. Brokers may enter the stock index futures market through brokers and dealers, which means that the expansion of brokerage business scope and the increase of income sources will also have a certain impact on the traditional business of brokers. After the mainstream investment concept in the market gradually changes to value investment, investors' demand for information and research will increase. Therefore, for the brokerage business, the current low-level competition focusing on attracting customers will be replaced by comprehensive competitive advantages such as talent, information and service innovation. The quality and professional level of employees in securities companies will determine whether brokers can retain customers and expand customers in the new market environment; In addition, for proprietary business, more quantitative analysis and risk control may be needed at the same time of investigation, including using stock index futures to avoid systemic risks reasonably; For underwriting business, in view of the great correlation between new shares and market trends, when the trend is good, the issue price of new shares can be set higher, and most of them perform strongly; When the general trend falls, the general issue price is set low and the trend is weak. With stock index futures, weak securities firms can hedge new shares by reverse operation and avoid some underwriting risks. 5, the impact of the introduction of stock index futures on the stock market A. The introduction of stock index futures will not change the long-term trend of the stock market, but only introduce a new futures variety, which is neither good nor bad for the stock market. It will affect people's psychology more and cause fluctuations in the stock market, but it will not change the long-term trend of the stock market. From the international experience, the index of stock index futures will rise before listing and fall after listing, but the long-term trend of the stock market has not changed. 1982 In February, before the Standard & Poor's 500 index futures were listed on the Chicago Mercantile Exchange (CME), the Standard & Poor's 500 index rose from 1 15.38 to 120.4. After the introduction of stock index futures, the index fell to 108.5438+0, down 9.79%. Although the introduction of American stock index futures led to a short-term decline in the index, it did not affect the long-term upward trend of the US stock market at that time. The stock market still depends on the development of American economy, and it has a steady upward trend for a long time. Hong Kong Hang Seng Index futures listed in May 1986, the Hang Seng Index hit a record high of 1865.6 points, and then began a two-month correction. After that, the Hang Seng Index resumed its upward trend. 1September 1986, the Singapore Financial Futures Exchange (SIMEX) launched the NIKKEI 225 index futures (Nikkei 225). On August 20th 1986, the Nikkei 225 index hit a new high 18936. Within more than one month after the introduction of the index, the Nikkei 225 index dropped from 18695 to 15820, with a decrease of 15.38%. After nearly two months' rest, Japanese stocks resumed their bull market, and 1987 65438+ 10/6 broke through the high point when stock index futures were listed. On May 3rd, 1996, Korea KOSPl200 index futures were launched in the long-term downward trend of the index. With the introduction of stock index futures, the KOSPI200 index rose by 17.5% before the futures listing, and reached a high point of 1 10.7 on April 29th. However, after the listing of stock index futures, the index resumed its downward trend. Taiwan Province Composite Index Futures was officially launched by Taiwan Province Futures Exchange on1July 2, 9981day, when Taiwan Province stock market was in a downtrend channel. Although the index was raised before the introduction of stock index futures, it immediately resumed its original downward trend after the introduction. From the influence of the listing of stock index futures in the above countries and regions on the stock market, we can see such a law: "It rises before listing, falls after listing, and the long-term trend remains unchanged". The key factors affecting the trend of China A-share market are the macroeconomic situation, such as economic growth rate, interest rate, exchange rate, policy factors, industry prospects, corporate profitability and other economic fundamentals. Stock index futures are investors' expectations of the stock market price, which is a new investment variety and cannot change the fundamentals. Therefore, in the long run, the introduction of stock index futures will not fundamentally change the price trend of the stock market. B. Stock index futures may make the stock market fluctuate to some extent. Stock index futures will play a role of "helping up and down" in the short term. After the introduction of stock index futures, market funds will pay more attention to index constituent stocks, and the performance of these index stocks will be more active. It can stabilize the stock price for a long time and make the stock market valuation more reasonable. In the short term, stock index futures will help the bull market to rise and the bear market to fall. In the bull market, investors buy stock index futures, and arbitrageurs will sell futures to buy stocks, thus accelerating the rise of stock index; In a bear market, investors who are bearish on the market outlook will sell a lot of stock index futures, and arbitrageurs will buy stock index futures and sell the spot, thus accelerating the decline of the spot index. However, the introduction of stock index futures can only be said to amplify the rise and fall of the stock market, and does not determine the rise and fall. The performance of stock markets around the world before and after the introduction of stock index futures Generally speaking, the index of stock index futures will rise before listing and fall after listing. Before the listing of stock index futures, in order to gain the right to speak of the index, institutions will adjust their holdings of large-cap blue-chip stocks, thus pushing up the index. After listing, in order to operate stock index futures, a deposit must be prepared, so some stocks will be sold to raise cash, which will lead to the decline of the index. Stock index futures will affect the fluctuation of the stock market in the short term, but in the long term, Friedman (1984) found through experimental research that the existence of futures market accelerates the balance of the spot market, reduces the bubble components in the stock market, avoids the blindness of spot price changes and market speculation, and makes the spot market tend to fluctuate less in the long term. The introduction of stock index futures may affect the fluctuation of A-share market. Before the launch, the market's rise came from the expectation of stock index futures, which increased the demand for heavyweights in the Shanghai and Shenzhen 300 Index and pushed the market up. After the launch, if the value of large-cap stocks is over-hyped, there will be short-selling motivation in the short term and the stock market may pull back. C. The introduction of stock index futures is expected to increase the capital scale of the stock market. Due to the characteristics of low transaction cost, low margin ratio and high leverage ratio, the introduction of stock index futures will reduce some investors who prefer high risk from the stock market to the futures market in a short period of time, resulting in a certain capital crowding-out effect, and the stock market funds will flow to the futures market. In the early days of share price index futures, an emerging market, there is often a transaction transfer effect, that is, attracting funds from the stock market to the stock index futures market. This happened to the Japanese when they first came to share price index futures. However, there is another function of stock index futures, which is to attract off-exchange funds. The development of stock index futures trading has increased investment varieties for institutional investors, provided effective risk management tools, promoted portfolio investment, reduced transaction costs for institutional investors and improved capital utilization efficiency. The short-selling mechanism of stock index futures makes institutional investors change from a single mode of waiting for the stock price to rise after buying to a two-way investment mode. Stock index futures provide investors with tools to avoid risks and expand their choice space. Therefore, share price index futures trading will attract a large number of off-site wait-and-see funds to substantially intervene in the stock market, and in addition, it can reduce the accumulation of funds in the primary market. The situation in the United States is that after the opening of stock index futures trading, the trading volume of stock market and futures market has been greatly improved, showing a two-way promotion trend. Judging from the current situation in China, due to the high degree of risk aversion of open-end funds, social security funds, insurance funds, enterprise annuities, QFII and other large funds, they do not participate or only partially participate in the stock market. In addition, China's high bank deposits can't find a way out, and the scale of OTC funds is huge. After the introduction of stock index futures with hedging function, the potential capital inflow is far greater than the possible capital outflow. Therefore, the introduction of stock index futures is expected to increase the capital scale of the stock market, and the trading volume and liquidity of the stock market will also be improved. D. Stock index futures will promote the introduction of stock index futures to optimize the stock market structure, and the allocation of funds will be seriously tilted towards index stocks, and the concentration of blue chip funds will be further improved. Damodarn et al. (1990) made an empirical study on the sample stocks of the Standard & Poor's 500 Index. The results show that the market value of the sample stocks of the index has more than tripled in the five years after the stock index futures trading. Small-cap stocks are easily manipulated, so in China stock market, it often appears that the increase of small-cap stocks is greater than that of large-cap stocks. Moreover, the stock index is driven by a few large-cap blue-chip stocks, so most stocks often fall and the index rises. After the introduction of stock index futures, the hedging and arbitrage operations of institutional investors will greatly increase their demand for index stocks in the spot market, push up the price of index stocks, and then attract a large number of retail investors to follow suit, further pushing up the stock price; The activity of non-index stocks will shrink day by day, and small-cap stocks will be gradually marginalized. Therefore, the introduction of stock index futures will make the market carry out structural adjustment of survival of the fittest, the blue-chip stocks in the large-cap market will be further optimized, and the small-cap stocks will be relatively weakened. To sum up, stock index futures can provide effective hedging tools for stock market investors, which may affect the volatility of the stock market in the short term, but will not change the long-term trend of the stock market. Stock index futures can attract funds into the stock market, and its "crowding out effect" on the stock market is limited, which will further enhance the blue-chip stocks in the market, while the small-cap stocks will be relatively weakened.