There is no fuse, which may be based on the characteristics of the stock index itself, because stock index futures is a risk hedging tool for hedging. If it is used for speculation, it is not impossible, that is, there are risks and of course there are benefits.
Here we should distinguish the stock index from the stock market. The stock index is based on several underlying stocks in the stock market. From the perspective of financial instruments, the stock index does not affect the trend of the stock market. Of course, in the actual environment, it is not uncommon for some people to make long or short positions in the stock market for the sake of stock index profit.
Stock index has the characteristics of high risk, high income and high threshold, and is superior to stocks or other financial instruments in flexibility, so it is suitable for institutions as financial instruments to hedge risks.
In fact, the relevant departments are also quite difficult to do. Let's just say that the market is not free and protect the interests of some people. Don't set it, it's a fan who loses money, and some people say it's internal collusion, harvesting hot money.