In binnace future we trade future contract of many crypto currency. If you see very carefully then  there is MARK PRICE.,which indicates that on this price the current contracts are traded. I noticed sometimes tthe price of eth is running at 180 but that contract sold at 180.90 or sometime 179.35 or around it.
In recently pump of btc the price went to the 7738 in spot market but in future it went over7802. So that's why this kind of things happen in future. I hope this information will help you to understand this concept.