Palm oil main force: the main futures contract will change, but its trend is different from that of stocks for a long time. In order to analyze the long-term changes, the trading platform will link the main contracts according to the maximum trading volume in a certain period of time. For example, the main contract in your picture was 1209 contract before, and now it will gradually move towards 130 1 contract, and the next one is 1305 contract. And the current main contract is 130 1. If you click on the palm oil main force, the trend will show 130 1 contract, and in a few months, it will show 1305 contract.
Palm oil can't be bought or sold. You can only buy and sell exact contracts such as 130 1 contract.
What is continuous and what is simulation is a kind of contract processing of trading platform, which cannot be bought or sold.