The indicator was described by B. Williams as fourth dimension – Trading Zone:
- If the current bars of AC and AO are trending up, it shows that the zone is up.
- If the current bars of ะะก and ะะ down, it shows that the zone is down.
- If the bars of AC and AO are differently directed then the bar is colored grey.
This version of Zone Trade indicator is made to show as histogram in separate window.