What does the Langer index mean?

Lange index is a series of indexes developed by the research center of Beijing Lange Information Consulting Co., Ltd., the core of which includes Lange steel price index, pig iron cost index and purchasing manager index of steel circulation industry. I think you should ask Lange steel price index, which includes comprehensive steel price index, excellent talent price index and plate price index. He reflects the operation of steel market price, which can be used as a reference index for steel market prediction in the later period according to the trend and experience.