1 Preserving value means that you have something in your hand. One way you operate is to preserve the value, in order not to let the goods in your hand lose money because of the market price. 2 Arbitrage, there are several types of arbitrage, 1) cross-market arbitrage, 2) cross-product arbitrage and 3) cross-contract arbitrage. Futures are generally across contracts or products. Cross contracts are easy to operate, and cross products are more difficult to operate. Cross-contract arbitrage is to earn the difference between different contracts. The operational risk of arbitrage is very small, and the income is certainly not as good as speculation. There is also a lot of speculation in the futures market. You can continue to ask me if you have any questions.