This chart has two parameters, box size and reversal, defined in ticks (minimum price change) for commodities. The program will attempt to select a reasonable default box size and reversal appropriate to the commodity and the data type requested.

With a volatile item, there will be times where the program selected parameters are too low and the resulting chart will be bigger than the space available and run over the top or under of the bottom of the frame. In this case, simply select a larger box and reversal size and re-submit the request. The opposite condition is also true, if the item does not have much price activity, you can end up with one or two boxes in the middle of the screen. In this case, select a lower box and reversal size.

You can change the box size and reversal numbers by entering your box and reversal numbers into the arguments box corresponding to the point and figure.

Another problem in selecting box and reversal size is the magnitude of the price of the security. IBM trading about $100 will produce a reasonable chart with a box size between 50 cents (4) and $5 (40). The reversal is usually 3 to 10 times the box size. While IBM is still trading in eighths, the indexes (S&P500, DJ30, NASDAQ100 etc.) can move in increments of 0.01 point, and the prices are much larger. With DJ futures trading around 10,000, and moving 150 points per day, 1 point at a time, a good box size might be 20 and reversal size of 50. The S&P 500 moves is trading around 1500 and can move 100 points / day, 0.05 points at a time, so a good box size and reversal combo might be 25 x 100 (1.25 / 5.00 points). The NASDAQ 100 is a problem, trading around 3000, and moving at 0.01 points at a time, suggesting reasonable box size and reversal of 250 x 5000. Our custom charts allow only 3 digits, so we have made a special case for this particular index. The box size and reversal will be multiplied by 10 internally. So 25 x 500 should work and produce the 250 x 5000 chart.