With the rapid growth of stock index futures market scale and trading volume, locking margin has become a problem that more and more investors need to pay attention to. The so-called lock-in margin refers to a sum of money that investors need to pay to ensure that investors meet the risk control standards required by the exchange during their positions. However, due to the volatility of the market, investors' positions may be risky and face the risk of loss. Therefore, the adjustment of locking margin has become the focus of investors' attention.

Compared with the stock market, the stock index futures market has stricter margin and higher pledge rate. Once the market fluctuates greatly, the lock-in margin of investors may be affected, which in turn will affect the actual income of investors. In the latest policy, the requirements of relevant departments for the lock-in margin of stock index futures will also be adjusted according to the actual market situation and investors' trading risks. Therefore, investors need to pay close attention to policy changes and adjust their investment strategies in time.

Generally speaking, the change of stock index futures margin cannot be completely avoided. In order to prevent risks, investors can avoid high-risk operations and reduce their own trading risks by controlling their positions and reducing leverage. In addition, investors can improve their trading ability and investment level by understanding the market trend and analyzing the market conditions, and avoid the margin risk of stock index futures as much as possible. Generally speaking, investors need to deal with investment risks with a steady attitude and get more benefits under reasonable risk control.