graph next to chess insights

hello,
on my profil page there is a graph below my rating graphs (next to chess insights).
what is its purpose?

Edit: I should have posted this to question and answers

For example you can slide the left side to the right to adjust the period of time you want to see in your rating graph.

@brudi the graph is your bullet rating I think.

thank you

You're welcome @brudi

@brudi
It is not bullet rating.
Bullet rating gets shown just the same way classical and blitz rating as well as any other types of chess-game rating get shown: inside tha graph area. They are each assigned a color and you get info when you mouse over a datapoint.
The mysterious graph at the bottom gives no such info.
If I look at the behaviour of mine it cannot be an aggregated number between all ratings, because it does not exactly follow rises and decreases.
My guess would be that it is a measure of how much one plays, but I honestly have no idea.
please hit me up if anyone finds out.