Stock index futures financing refers to a capital cooperation in the futures market where investors entrust funds for wealth management. To ensure fairness and transparency in the capital cooperation, investors and traders typically negotiate and agree on an "Account Entrustment Operation Agreement" or "Capital Cooperation Operation Agreement," signed by representatives of both parties, outlining the rights and obligations of each side.

During the financing process, to ensure the safety of the investor's funds, the trader is required to deposit a certain amount of risk margin into the account. The investor then lends funds based on this margin at an agreed ratio. After both parties inject capital into the account, the trader takes full responsibility for trading, while the investor oversees supervision and risk control.

Generally, to hedge risks or lock in loss limits, positions are usually held in both directions (long and short), but at different price points. The decision on where to lose and where to profit depends on the market trend (macro-level policies) and the direction of stocks or indices resulting from the博弈 (competition) among different interest groups (e.g., brokers often collude with several others rather than acting alone). Sometimes, intentional losses in stock trading are offset by significant gains in index futures contracts, resulting in an overall profit.