Quarter theory and whole numbersThis is an indicator that marks off Major whole/quarter levels
Between each major whole they are 1000 pips and that can be quarter and give you major quarter levels of 250 pips
Each of the major whole number can be divided into 10 - 100 pip ranges(giving you minor whole number), and you can in turn quarter these to give you 25 pips.
This is the lowest value you would need as price moves in 25 pip.
You can use this on any market as long as you can figure out the conversion from price into pips for you assets (This varies).