You choose the box size. The box size is typically an easily divisible number. For example, if you were constructing a point and figure chart on gold futures, you might assign each box the value of 3 points. If a rally were under way and Xs were being plotted, a new X is added to the top of the column with each 3-point gain. If prices were falling and Os were being plotted, an O would be added to the bottom of the column with each 3-point loss.Box Size