Downward trend line: Connect the low and sub-low points and draw a downward trend line.Downstream trend channel line: Downstream trend channel line is formed by connecting the K-line solid high point to the lower high point and the lower low point.As shown in the picture: in a firm deal, buy short at a high point and sell at a low point.Buy more at lows and sell at highs.To do high throw low suction.It is important to note that when the market price breaks through the downward trend line or the downward trend line, there is often a strong fluctuation in the market.