Item D, stock index futures arbitrage mainly includes short-term arbitrage and intertemporal arbitrage. The result of futures arbitrage is that the total profit and loss of futures is just equal to the difference between theoretical futures price and actual futures price, so in futures arbitrage of stock index futures, arbitrageurs do not have to bear the risk of price changes; However, in the intertemporal arbitrage of stock index futures, due to the influence of many factors, the actual price may often deviate from the theoretical price. Arbitrage analysis and trading based entirely on theoretical prices may face greater uncertainty and bear certain risk of price changes.