If it is a short time and the price is outrageous, there are the following possibilities:
1, because a contract is not the main contract, the transaction volume is small. Suddenly, a daredevil gave the wrong order. Originally, he wanted to place an order for the main contract, such as 1205 contract at the market price, but he bought 1206 or 07,08 or something. Therefore, these non-main contracts were rarely concluded in 2006 and 2007. If there is a price difference between the two contracts, you can print a long upper shadow or a lower shadow without a market price list.
2, there are large households, in order to stimulate the popularity of bulls (or bears), deliberately raise the non-main contract. Because there is no follow-up payment, it will fall back soon. Form a long shadow. (and vice versa).