Zheng Mian client Android version is a spot trading platform serving the real economy. Zhengzhou cotton trading market has computer client and mobile phone client. Control when and where to trade at any time, two-way trading can buy up and buy down, and overnight fees can be traded during the day and at night. This is actually the overnight interest of positions, also called warehouse interest. After investors buy or sell gold or silver, they will not close their positions within the same day and will generate overnight interest. When trading precious metals on the official platform in Hong Kong, the transaction cost mainly consists of three parts: handling fee, spread fee and overnight interest. Under normal circumstances, the transaction spread is $0.5, that is, the standard contract of trading 100 ounces will generate a spread fee of $50, plus a handling fee of $50. In addition, if investors hold positions for more than one settlement cycle, they will generate overnight interest, that is, overnight fees.