After the iron ore futures price is lowered and the profit margin of steel is expanded, the thread is driven down. According to the relevant public information of inquiry, it is easy for iron ore to continue to fall, which leads to the expansion of steel profit margin, which in turn leads to the compression of downstream demand and forces the price reduction of rebar products. To sum up, the price reduction of futures iron ore will drive the thread to fall after the profit margin of steel is expanded.