In foreign exchange transactions, there is a very common form-box type. Investors often refer to the box shape as rectangle or box, which is a typical arrangement. When the exchange rate in the market rose to a certain level, it met with resistance and turned back, but it was quickly supported and rebounded, but it was blocked again when it rose to the same high point last time and supported again when it fell to the last low point. These short-term highs and lows are connected by straight lines respectively, and a channel can be drawn, which is neither upward nor downward, but develops in parallel, that is, in the form of a rectangle.

Generally speaking, in the foreign exchange market, when the market goes up and down, it may appear in both directions, and the long and narrow rectangle appears more at the original bottom. After breaking the upper and lower limits, there are buying and selling signals, and the fluctuation amplitude is usually equal to the width of the rectangle itself. When it breaks through the upper resistance, it is a "buy signal". On the other hand, if it falls below, it is a "sell signal". In the process of rectangle formation, unless there is sudden message interference, its transaction volume should be decreasing continuously. If there are effective technical forms such as deviation or triangle in the process of form formation, the form may fail. When the price exceeds the rectangular upper limit, there must be more intense market cooperation; On the contrary, the same is true of falling below the lower limit level.

When foreign exchange trading is going on, if there is a breakthrough in the box, then the exchange rate in the market will often reverse, which usually happens on the second day of the breakthrough. Back pumping will stop at the top line level, and the false recovery after falling below the bottom line level will be blocked.