Stock index futures are standardized contracts based on stock indexes. It is a derivative financial instrument, which has three functions for investors: speculation, arbitrage and hedging. For retail investors, there are certain thresholds, technical thresholds and capital thresholds, because they can be long or short, and follow the margin and debt-free settlement trading mechanism. Therefore, if the direction is wrong, they will easily be forced to close their positions under the condition of insufficient funds. So the risk is great. According to the transaction details published by CICC, for example, if you buy 1 hand IF300 on a certain day, assuming that the number of points at that time is 3000, you have to pay a deposit of 3000 * 300 * 20% = 180000, assuming that the last number of points on that day is 2950, then you lose (3000-. Then your margin account is deducted 15000, and due to debt-free settlement, it should be maintained at the margin level of 2950 = 2950 * 300 * 20% =177000, so you must withdraw177000-(180000).