a common perception in the market that the price of cotton is higher than that of VSF

There is a common perception in the market that the price of cotton is higher than that of VSF, and there is correlation between the two, but is this really the case? It appears to be “abnormal” that the price of cotton and VSF has been much close recently and due to the continued high price of cotton from 2021 to the second quarter of this year, the price difference with VSF has hit a record high of more than 10,000yuan/mt. According to the so-called correlation, the price of VSF should have been expected to rise notably, but it fails to jump on the bandwagon. Looking backwards, VSF had been higher than cotton for a long time in the past two decades