This counts the number of up or down thrusts over the previous N days and creates a total (up thrust - down thrust) to produce the graph.
It also optionally will include "run days" as part of the same count.
The idea is that it gives you an indication of the strength of the current trend (and can possibly help you spot it reversing ;))
For more on thrust days see:
And for more on run days see:
發行說明
Added additional feature to display the actual thrust days and run days on the chart . Gives a little more insight into exactly what and where is causing the totals displayed.