X is created when the price increases by a given amount, called the box size. O is created when the price falls by the size of the box.
X and O overlap each other, respectively, and often form an X or O series.
The size of the box is set based on the price of the asset and the preferences of the investor.
The formation of a new column of crosses or zeros occurs when the price moves against its current trend and does so by more than the amount of the reversal.